Anal again?

So me and my fiance have done anal before and it was amazing! Only thing I was high from medicine my doctor gave me! No I didn't abuse it, but had never had it before that so obviously it was gonna get to me! Anyway. We've tried again I'm 11 weeks pregnant and his dick is so big the head hurts when it goes in after the head is in its painful but I get used to it!! He usually tries to finger it, but it hurts when he puts more than 1 finger... Really want advice!