Manual cycle option

Is there a way to change your cycle prediction? I had an irregular cycle due to pcos and then I had a miscarriage which has one of my cycles at 76 days so it keeps giving a 38 day cycle predicted. I am now on clomid and for the past 4 months I am on a steady 30 day cycle now. I would like to force it to a 30day cycle so the ovulation is right. I like tracking in this app but I keep having to use another to predict ovulation.