<P> Abby's next relationship is with Dr. John Carter . Abby discovers Carter shooting up on painkillers during season 6 . She tells the senior doctors about it, and at their urging and with their help, Carter enters a rehab program . Once he returns, he sees Abby at an AA meeting . She tells him that she is a recovering alcoholic and had been sober for five years . She agrees to become his AA sponsor . Abby and Carter develop a very strong friendship, which strains her relationship with Luka . Several months later, Abby has a particularly horrible birthday and starts drinking again . When Carter catches her having a beer a few weeks after she was attacked, he confronts her, and she tells him not to worry about her . When Dr. Mark Greene passes away at the end of season 8, Carter seeks solace in Abby . She returns to her AA meetings, telling Carter she is doing it for him, and they are a couple throughout season 9 . Abby continues drinking on occasion, however, and Carter compulsively tries to "fix" her . At one point, Carter is ready to propose to Abby at a special dinner he's arranged for her, but at the last minute, he puts the ring back in his pocket; although they discuss it briefly in a later episode, he never proposes again . Their relationship is badly strained when Carter's grandmother (Frances Sternhagen) dies, and Abby's brother, Eric, conclusively diagnosed with bipolar disorder, acts out at the funeral and falls into the grave . Soon after, Carter flies to the Congo and joins Luka, who is volunteering with Doctors Without Borders . On his return, Abby is extremely hostile towards him for leaving without explanation . When Carter goes to Africa for a second time to recover the body of Luka, who, in a plot twist, has not actually died, he sends Abby a break - up letter, and their relationship finally ends . Just as with the end of Luka and Abby's relationship, Abby and Carter remain close friends after a period of distance between them, especially when Carter returns to Chicago with his pregnant girlfriend Kem . </P> <P> Abby briefly dates a medical student named Jake in season 11, but their relationship fizzles when Abby does not respond positively to Jake's desires to stay in Chicago to be with her . She also begins to grow closer in her friendships with Dr. Susan Lewis and Dr. Kerry Weaver . While she is not especially close to Sam Taggart, they are usually on good terms . Dr. Lucien Dubenko, Chief of Surgery, is attracted to her for some time, but Abby does not return his affections, seeing him as just a friend . Nonetheless, Lucien remains rather protective of her for several seasons . </P> <P> In season 12, Abby rekindles her relationship with Luka in the episode "The Human Shield" when her attempt to vent her frustration at him turns into a kiss and subsequently sleeping together . Initially, they decide to remain friends, but soon become lovers, noting that they always seem to find their way back to each other . Three weeks into their relationship, it is revealed that Abby is pregnant . Despite clearly wanting another child, his own having perished in Croatia, Luka states that he will support whatever choice she makes, as long as they can still remain together . After a week or so of uncertainty, Abby decides to keep the baby . Luka proposes to Abby while she is pregnant, but Abby is not comfortable with the idea because of her past problems, and later claims she' doesn't need a white dress' to prove she loves him . Their baby, a son named Joseph (after Luka's father), or Joe for short (after Joe Frazier, the boxer whom Abby's long - disappeared father was a fan of) is born prematurely by emergency C - section at the beginning of season 13 . Abby has to have an emergency hysterectomy . Joe spends several weeks in the hospital's NICU, requiring surgery during his stay . Abby and Luka's relationship becomes strained during this period, but they appear much happier in later episodes, caring for their now healthy baby boy . </P> <P> Throughout season 13, Abby is shown growing into her role as Joe's mother, first by taking time off to be with her seriously ill baby, then by participating in activities like Mommy and Baby classes and walks in the park, and then later by gradually reintroducing herself into the ER world . Mid-season, tension develops between Abby and Luka, partly as the result of Luka's apparently paranoid behavior regarding Curtis Ames (Forest Whitaker), a disgruntled former patient who has sued Luka due to a stroke he suffered that cost him the use of his arm . Not realizing that Ames approached her and Joe in the park posing as a friendly stranger, and has been stalking both her and Luka for some time after he lost the case, Abby brushes off Luka's concerns . However, Ames breaks into Abby and Luka's apartment with a gun, and demands to see Luka . Abby tries to bargain with him, telling him that she is a recovering alcoholic, and recounting an occasion where she felt she had hit' rock bottom' . Luka is taken hostage, threatened and has his hand crushed by Ames, but survives when Ames commits suicide . In the next episode, an emotional Abby asks Luka to propose to her again . She says if they got through the shooting incident and the Curtis Ames nightmare, they can get through anything - he proposes and the couple get engaged . Later Luka realises that Abby is hesitant about planning the wedding, so he decides to prepare a surprise wedding for her . At first, she has her doubts but eventually she agrees and asks Neela Rasgotra to be her maid of honor . </P>

When do abby and luka get back together