confused, help.

So I had a miscarriage Feb 3rd, and I stopped bleeding within 5 days. I have had sex about three times since then. A few days before my miscarriage all of my symptoms subsided. I now have those symptoms again, the nauseous feeling in the morning, every time I eat, and hungry a lot. Is it possible to conceive that fast? Also, I had my HCG levels checked Tuesday and they were at 1, so that is out of my system. I'm so confused and nervous to take a test because I don't want my heart broken when it says negative.