if he was deep inside he probably found your cervix, its at the top of your vagina , the neck of the womb.
it can get scratched and made to bleed.
sometimes when a lady has gyno exam and they take pap smear from cervix it can bleed.
It should heal up ok like any other cut, or abrasion.
but tell bf , its a delicate area inside your vagina ans while its natural he wants to feel around and explore you, he have to go gentle .