Do I squeeze them?

I am pregnant and my first born daughter is still breast feeding but I feel like nothing is coming out anymore! I tried to self express but I can’t seem to squeeze hard enough to get anything out!! Where before I would try to express some just to make sure my ducts were clear and milk would come out no problem. I don’t want to pump and check because I’m told not to in fear of getting early contractions.

My daughter is about to be 2, I think she’s definitely had her fill but still wants to nurse. How can I check my milk supply?