Ovulating on the pill?!

S!

I have a quick question! I’m back on the combo pill, it is my second month taking it since my miscarriage in May. I recently had forgotten to take some pills and decided to buy an ovulation test. I had my period earlier this month then stopped and bled again, (withdraw bleed??) All of them ovulation tests have been “negative” as the test line isn’t as dark as the control line but there is unmistakably a line. I was wondering if anyone knew why? Was I ovulating? Or is there a different reason the tests are detecting lh?