Spotting in early pregnancy..

I just found out I'm pregnant on Saturday. My lines on my tests have continued to get darker. I went to the docs and confirmed pregnancy and they took my blood to test my levels which I won't hear back until tomorrow afternoon. but I'm only 3 weeks and 3 days (haven't even missed my period) and every brand of test I have taken (5 different kinds) are saying I'm pregnant and have noticeable lines, I even got a positive digital clear blue test on saturday. I just went to the bathroom and I'm spotting. Is this normal? I'm so scared that I'm losing this baby :(