I think I know what is meant by “irregular.” Mine were. It was rare, if ever, for me to be regular. I might go 45 days between cycles, or it might be a different number of days. This started about as soon as I started having my cycle at the age of 11. Not knowing any better (I wasn’t Catholic at the time, so NFP wasn’t available), I just accepted it for what it was. I don’t have that to contend with anymore. Next month marks 10 years of having had a hysterectomy. Also, I’m not married. If all that was the opposite, I would have contacted my parish about the classes for NFP. I know it’s rough, but hang in there.