Pregnancy after period?

So this last weekend I had what I thought was a period. Bled from Friday to Monday. Not super heavy but still seemed normal. Tuesday I took an OPK and it was high. Took a pregnancy test and it was positive. I am so confused as to what’s going on and now can’t shake the thoughts of am I actually pregnant? Is it healthy because of that “period” and am I more at risk for miscarriage? I hate these thoughts