Is there something wrong with me?

So I’ve already done sexual things and have had sex before, and it sometimes feels good, but the majority of the time it feels like something is ripping out my insides. Like let’s say my boyfriend is fingering me and right in the middle of it I’ll get a sharp pain and it will hurt so much that i have to push him away. Now i know lubrication isn’t a problem because we have tried doing it with both my wetness and lube, but it still hurts. I’m my comfortable enough with my boyfriend, and he never forces anything upon me and always tries to make me feel comfortable, but no matter how fast or slow he goes, I’ll still get that sharp pain. We were each other’s first, so could it be that I’m still not used to the sexual activity or is there another issue?