They usually say to watch your periods for 6 months......meaning track the days. If they are 28-30 days apart, then you can assume you are regular........but, that isn't always true..... I had irregular periods for 3 years, and started regulating (27-28) days in Oct of last year. I got a funky period in Feb......it came 5 days early, and was light spotting...took a test and it was negative
But following month, waited again for period and nada.......I'm now 11 weeks PG
So, you don't necessarily need a regular flowing period to ovulate and conceive.... doc told me to " do it" on days 12, 14, 16 of your cycle. So, I guess it doesn't hurt to start tying now......