Flying Pregnant with Toddler

Hi! I've searched everywhere for an answer but nothing specific to my situation came up. I'm flying from Europe to the US 20 weeks pregnant with an 18 month old...alone! I booked the trip before I was pregnant. Here is my dilemma: I have to check my stroller at check-in since my departure airport does not allow gate check for strollers (security or safety issues they say). They have loaner strollers so I'll be okay at that airport but I have a layover of 1 hour 50 minutes to get between terminals & customs in Chicago O'Hare. My toddler can walk but chooses not to walk if I'm there to carry him. I cannot carry him the whole way to the next flight and I can't get the stroller at the gate. called the airline & they can only get me a wheelchair if I can't walk myself. Otherwise, they had no clue. My next step is to call Chicago airport special assistance. I'm also going to ask if I can pick up the stroller in customs since I have to pick up my luggage & re-check it but not sure if that is allowed! Any tips on this situation?? Any advice would be appreciated! Does anyone know if there are loaner strollers in O'Hare (I don't think they do!)? I have flown pregnant before & flown with my baby but never those 2 situations together & never alone! Getting a bit nervous. Thanks!