I Have Always Had A Normal 28-day Cycle But It

I have always had a normal 28-day cycle but it wasn t until this past June that my cycle became so irregular. During my June cycle I had a really heave flow and bad cramps that period also lasted for about 2 weeeks which is too long as I normally last about 4 days. Ever since then my period does not come every month I had a 60-day cycle. Which lead me to think I had a miscarriage. Me and my husband have been trying to get pregnant since July we just recently started using the ovulation tests in November and had sex on my ovulation days and still no pregnancy. Anyone know what may cause this?