Help please..

So I had sex nov 25 3 days after my cycle ended then I had sex Friday dec 4. I'm 3 days late on my cycle. I've been having pains in my side. I've been really tired I took 3 88 cent pregnancy test from Walmart and they came out negative. I read that some test aren't designed to detect so early.... What do you suggest? I've been feeling sick. I'm really moody I have the clear discharge and everything 😩 We didn't use protection. & he keeps telling me I'm pregnant. Please help!!