3 years and nothing??? What to do?

Me and my husband have been ttc for about 3 years now. After I had my son in 2010 I went on bc. I first went on mirena, then on the pill and then the depo which is what I was on for a good couple years. My periods have always been irregular. But now if I do get them it's just very very light spotting here and there for a day or two. I don't know what to do in order to increase our chances. Should I go on the pill to help regulate my period for a while? Any advice is welcomed please.