Irregular Periods

Krista
Hey, so I've been off the pill for about 6 months now. The first two months off it I had regular periods but since then my back has been breaking out non stop and my periods are now average of 40-50 days apart. Should I be concerned? Has anyone else had similar experience? My husband and I want to start having kids soon, but it's hard to know when I ovulate. Just really frustrated.