Worried but not

Maybe three weeks ago I started to feel like I had to pee and when I would go to the bathroom nothing would come out and the feeling comes and goes and I told a friend about it she said it’s probably because I’m dehydrated and I am sexually active and idk if it could also be an std but I already had an std test back in end of November and I was clean and honestly idk what to do I’m drinking more water peeing when I need to pee my pee doesn’t smell bad it’s just this feeling thy comes and goes that worries me