Vagina getting bigger?

Idk how else to explain this or how weird it is going to sound, but i truly feel like my cervix is getting wider....I’ve always been super tight, like to the point where men have told me it hurts sometimes to have sex...but lately i feel like it’s getting wider...my bf and i just had sex and he didn’t even cum after almost half an hour...i feel so self conscious and he keeps reassuring me that it’s still tight and small and feels just as good as always but I’m so scared that it’s somehow getting wider. I’m not pregnant, at least i shouldn’t be because I’ve had 2 periods and normal cramps/heavy af flow for 5 days and by now i would be right at the end of the first trimester and I’ve taken 12 tests and all negative so...yeah I’m 99% sure I’m not bc the last test i took was about 3 weeks ago. But idk why else i would feel so strongly that it’s getting bigger...am i insane or sound stupid?