Uy, that sounds uncomfortable! But if you're having belly pain at 35 weeks, please call your OB or go to the hospital right away, hindi dapat i-guess kung bakit ang sakit, lalo na malapit na kang mag-deliver. As for costs, it really depends on the hospital (private vs public) and what they need to check, kaya better to ask your doctor or the hospital directly so you're prepared. Sending you hugs, take care of yourself!