Two Periods After Skipped One?

Hey guys! My period is usually normal, and like clockwork. I occasionally skip a month, maybe once a year, but my doctor said this isn’t a cause for concern since it is usually so regular and can be caused by stress, etc. I have really bad anxiety.

I’ve lost 25 pounds in about 2 months, as I’ve been trying to lose the weight I gained in Uni, and I completely skipped my period in June. It eventually came at the beginning of July (about 2 weeks late) and stopped after about a week. It’s 9 days later and I’ve just started another period?! There’s no possibility that I could have been pregnant or anything like that. Has anyone else ever experienced this? Is it because of the missed one in June? Help!!!