I travel to work each day on the train, about a 40 minute journey each way. I’m currently 9 week pregnant and suffering from morning/evening sickness. I have thankfully managed to avoid being sick on the train so far but I’m very worried about it happening. The train journey in the morning is OK as the train is fairly quiet, so I just find a seat very close to the loo, but the journey back is horrendously busy. Several of the seats closest to the loo are priority seats and I do sit in those sometimes if they are free and the non priority ones close to the loo are full.
I’m just wondering really whether this is an ‘adequate’ reason for sitting in them and, if someone else who needed one of the seats ever asked me to move, whether it would be really obnoxious of me to ask them to ask someone else in a priority seat instead? Obviously if nobody moved (or everyone sat in them needed them) then I would move. I wouldn’t allow someone who physically needed the seat to not have one as it wouldn’t be the end of the world if I threw up somewhere other than the loo… I’d just rather not 
I have name changed for this just in case everyone thinks I’m a terrible human being for even considering it. I have heard people in real life say that they wouldn’t offer their seat to a heavily pregnant woman as it’s their choice to have a baby, so I’m not sure how people would feel about morning sickness!