I don't want to have sex with a very pregnant woman and telling her so
Is there a reason you don't want to sleep with her?
I'm scared to touch her, mainly because of the strong hormonal scent.
It is okay to not be with somebody even if you already had said yes. A person can stop at anytime and refuse to continue at anytime. You will feel bad if you go ahead and you didn't want to.
These are my own views towards pregnancy and I'm okay with it.
Nobody should feel pressured into having sex. You should tell them how you feel nicely and ask them to respect your feelings.