What’s going on?

Hello everyone, so I had twins back in October (first pregnancy), my cycle started back up in December (all completely normal 30 day cycles) then May comes around and I don’t get my period. Took a test- negative. So I just said whatever probably my body just still working itself out. Since then my periods have been anywhere from 6-8 weeks apart. Can anyone tell me if this is normal. I plan on making an appointment next week for my gynecologist but wanted to see if this was normal first. Also, I have no history of my periods being inconsistent. Thank you.