TTC while BF

My husband and I have started trying for baby #2. I am currently still BF my 7 month old and have not had my period return yet. The end of last month (around the 27th) I randomly took an ovulation test, which was very obviously positive. I stopped testing and started again today. My test today was positive too (test line was as dark as control line.) My question is, do the hormones I’m producing from BF making me have positive tests? I find it weird that the two times I decided to check, at different times of the month, I got a positive. I took a pregnancy test this AM as well and it was negative, so that’s not why. Any thoughts???