Painful Sex

‼️please read and help me figure this out‼️ so my boyfriend and i both lost our virginity’s to each other and we’ve been together for awhile now, when i first lost it the first few times sex was painful but i know that’s normal and it got better and now it isn’t painful but it does hurt when he first goes to put it in and it doesn’t feel good until it’s all the way in then it’s normally fine after one or two strokes, well last night we were having sex and it fell out a few times it fell out again and he went to put it back in and it was burning really really bad and was really painful so we stopped, does anybody know why this could be? it almost always hurts when he first puts it in then it gets better and i never thought anything of that but it was weird that it was so painful last night, i have never once forgotten to pee after we have had sex there’s never been a single time i forgot, do you think it could be an infection or that we were too rough or i had a weird reaction to the lube? we used to use the same lube before and stopped using it cause it was a little pricey and burned just a little bit after we would get done so we used spit but we have started using the lube again because the spit wasn’t enough, we weren’t super rough but it definitely was a little rough i was in doggy so we were going pretty fast or does it sound like an infection? maybe it could’ve been too rough plus i had a weird reaction to the lube at the same time? let me know you’re thoughts please!