Baby 2, breastfeeding, periods, oh my!

So starting to think about trying for baby 2 and have a few things on my mind. I have been getting wicked migraines that made me throw up (more than normal), so I thought to test in case it was a symptom, even though we weren’t specifically trying. Got a positive from a digital and after a flood of emotions decided to test again and it was negative. Then 2 the next day we’re negative, so I figured a weird error. I am still breastfeeding some and have not had a period yet, so I know things are unlikely. Anyone in the same boat? Any ideas? Really needed to think out loud.