Late period could I be pregnant?

So we had unprotected sex and twice with no pull out method, so the swimmers were definitely in on my heavy ovulation day 3 days later I notice light bright red spotting and 2 or 3 days light brown then I had a fever felt bloated and nuasea. I'm now 6 days late, symptoms dry eyes, soar breasts, nipples tender, nauseas, emotional, constipated, gassy like movement, tired often take naps. I took 3 tests 1 or 2 days late all came back negative. I think conception happened fathers day so I'm almost 3 weeks. I think I had a miscarriage last month so could my hcg levels be off? I feel very different. When is it a good time to test? Anyone have similar and turned out to be pregnant?