Positive pregnancy test during ovulation time.

My husband and I have been ttc for 5 cycles now. I had a regular period two weeks ago and then a few days ago I had bright red blood on the toilet paper one time after I peed. I had just a very scant amount a couple times after that. Yesterday afternoon I went to the bathroom and I had small amount of dark brown blood on my underwear. I wiped and there was just a small amount on the toilet paper. Last night I felt sick out of nowhere and vomited. So I was googling in the wee hours of the morning and someone had said this happened and they were pregnant. So I took a pregnancy test and waited maybe a minute. I thought I was being silly even testing so I went back to bed for half an hour to an hour. I had left the test on the counter and when I got back up it was positive. I have so many questions. Is it possible it could still be correct even if it was past the 10 minutes later? And how could I possibly have a positive pregnancy test if I just had my period? Thanks in advance!