Help please

I've been on the pill for the past 3 and a half years, I ran out about a month ago, and so I've been off the pill for just over a month and I was supposed to get my period 3 days ago, could my period be mucked up because I stopped my pill? Or can my period get mucked up by quite a bit of weight loss in a short period of time?? I'm freaking out please helppp