Pain during and after sex

I’ve been having pain during sex, penetration and when he pulls out. I thought it was nornal because it was like my first couple times and probably not enough lubrication but then i’ve been getting like a burning/ irritating feeling after sex for long hours so i’m not sure if that’s normal anymore. I tested negative for STI’s so i’m not sure what it is. would anyone be able to help me if they know what it is?