Painful sex!?! I don't know why? HELP!

Okay so me and my partner have been having regular sexual intercourse for about 4 months. Ever since the first time (which was very painful), I have pain. The pain is usually just in the beginning. I usually cum before he gets inside me and after he's in (taking it slow and painful) it starts to feel good. But today I noticed when he was in really deep, it hurt. So it hurts in the beginning and now it hurt when he was in deep. I don't know what to do and I can't see a doctor right now. I don't think it's an infection because there is no pain or itch when I pee. My periods are regular I guess (0-6 days earlier then the last period every month). There is one thing, I'm usually dry, not very wet, down there. Could that be it? We use Lub but maybe we need to use more? I'm not really sure. This has me really stressed out so any help or advice will be much appreciated.