Travel insurance. May cost you a bit of money given your pregnancy, but definitely what you need to do.
I've used it when my husband and myself both started puking on our way to the airport and weren't fit to travel back from a trip to the USA and therefore had to reschedule our flight from that night. It was easy to claim back and we had no issues whatsover with claiming with either of them. This included flight change costs with the long haul airline, plus a completely new easyjet flight to get home to Scotland and a train ticket to get home, because we couldn't fly into our closest airport as the flight was sold out, and the extra accommodation and food costs, urgent care appointment and anti-nausea Rx, (which was a bit crazy to have to use up medical resources for a puke bug and I can tell they were annoyed, but needs must when you're claiming on this kind of stuff....). No problems, I had an excess of £50 and hubby had an excess of £100, so it was still worth it. I have an annual policy through Amex (contracted to Axa) because I have a pre-existing condition so it's cheaper and he had a single policy through John Lewis (contracted to Ageas).