Pain during sex

So I first had sex when I was 19, with the guy I love, we are still together he is the best, I love being with him. First sex that I had was last year in July and it was like normal not too painful and only little blood. But after that I started having pain at the beginning of sex. So first time when he goes in vagina it is really bad pain which is going worst when he is going deeper.. After 3-4 times when he goes in and out pain kind of goes away. I thought it was normal when it was happening for few days after first time. But It never disappeared. So I am a bit worried about it. Is that normal? Or it might mean something dangerous? Not sure...

I'd def ask a doctor

Obviously see a doctor just in case but, are you using lubricant? Even making sure you are naturally lubricated beforehand is sometimes not enough and can lead to painful penetration. Try out a water based lubricant and like mentioned before, make a doctors appointment just in case.