TTC with super Irregular cycle

My fiance and i have been TTC for about a year, mainly just unprotected sex all the time. I'm using this app to hopefully be able to pinpoint when I'm fertile. My cycle is so messed up so it's been difficult to figure it out. Some times i will have a period every 6 weeks, sometimes longer. When i was taking birth control to regulate my cycle i began having 2 periods in a month. I'm just looking for some advice and tips on what has worked for other women that have issues with an irregular cycle.