I Had Sex Before I Put It IUD Now I'm

I had sex before I put it IUD now I'm having like symptoms of pregnancy like I'm going to the bathroom a lot I threw up yesterday I almost threw up again today I go to the bathroom and my P is yelllow this is kind of gross I'm sorry but it comes when I wape myself it's brown. I've took in tests and they've come out negative I don't know if it's too early to do the tests I had sex on 30 July and I'm having back pains like back in on I eat my favorite cheeses I know we can eat like I used to eat like five of them now I eat like three of them