Weight question

I start dieting about 6 weeks ago and I’ve lost right around 20 lbs. no crazy diet, I’ve been doing weight watchers, and exercising more frequently. My question is could that cause my periods to be more irregular before regulating? I’ve always had somewhat irregular periods, but they are almost always on the long side. 30-35days+. The past two months they have been 21 days and now this one was 22 days. I had an ultrasound and blood work done a few weeks ago and all my hormones and everything came out normal, so I’m just wondering if hopefully soon my cycles will regulate better and be longer or closer to the 28-30 day range? I want so bad to fix this so when my wedding gets here in September we have success trying to have a baby!