Could it really be?

It's been 5 days since I started a natural MC. My bleeding is now super light so last night my husband and I had unprotected sex. I had a feeling I was ovulating (no clue why), so I took a test this morning and it was +. I know it's not leftover pregnancy hormone because I took a test yesterday to see that hopefully my levels we're back to 0, and it was -. Could I really be ovulating again this quickly!? Could a pregnancy this soon after MC be viable?