Pain during sex

I had a miscarriage of two beautiful twin babies back in April. Ever since then whenever my boyfriend and I have sex it hurts about 40% of the time. Almost like he is too big for me or like my cervix is low. Anytime he goes deep I tap out because it hurts so bad. I've gone to a gynocologist and they said nothing and I've been tested for STDs. Does anyone else deal with this or have advice?