Chicago Med EP: Viewers 'Should Definitely Be Questioning' Who Is Hannah's Baby Daddy

If you think you know who the father is of Hannah's unexpected bun in the oven on Chicago Med, think again.

During last week's episode, the OB-GYN discovered that she can't be a surrogate for her sister because she's — surprise! — already pregnant. The last person Hannah dated was Mitch Ripley, so that would make him a likely baby daddy candidate... except for the fact that, as many TVLine readers have pointed out, the two split up quite a while ago. And if that timeline doesn't add up, then who is the mystery man that knocked up Hannah? Well, the doc showed up at Dean Archer's house earlier this season with dinner after his ex-wife died...

"I think the audience should definitely be questioning" who the father is, showrunner Allen MacDonald tells TVLine.

But just as viewers didn't witness what happened between Hannah and Dean after he invited her in, "the audience has no idea what happened off-camera" between her and Ripley, either, MacDonald notes. "So when they say the timeline with Ripley doesn't match up, and the timeline with Archer does, they don't see everything [that] Hannah's up to."

Regardless of who the father is, some big conversations are ahead for Hannah in this Wednesday's season ender (airing at 8/7c on NBC).

"She's going to have to tell a few people. She's going to have to tell her sister, and she's going to have to tell the baby's father," MacDonald previews. "So those are the things that are kind of hanging over her head as she goes into the season finale."

While Hannah didn't look too thrilled as she stared at the positive pregnancy test, MacDonald says he "wouldn't even term" her feelings about it as "happy or unhappy."

"I think she's stunned and shocked, and she didn't expect this result," he explains, adding that the seeds were planted for the pregnancy twist when Hannah didn't appear in Episode 20. "Maggie says in that episode, 'Hannah's home sick, too. It's not just the nurses.' So we've been kind of setting it up. But I think even though she's an OB-GYN, she didn't even imagine that that was what it was."

Elsewhere in the season ender, Dr. Charles' daughter Anna is brought into the ED following a car accident, which is "going to bring up a lot of family history issues between him and his daughter," MacDonald previews.

In bringing back several important people from his life — his daughters, his mother, his protégé Dr. Sarah Reese — and introducing "a push and pull relationship with Jackie," this season has shown that "Charles is lonely, and he's a great psychiatrist, but that doesn't necessarily mean he is good about his own life and the people in his life," MacDonald continues. "I think he's made a lot of mistakes, and I think he knows that. ... So the idea [for] the end of the season is for him to go to the ultimate source of the well of pain for most people, which is family history, and force him to deal with it, and the accident with Anna is part of that."

Chicago Med fans, hit the comments with your hopes for the finale!