Irregular cycles

Last July I went off my birth control.. Ever since then my cycles have been anywhere from 35-52 days long.  It has made trying to conceive extremely difficult even with using opk's.  Does/did anyone else have this issue once they got off BC? And how long did it last? I used to have regular cycles, so this is very frustrating.  Any tips to ovulation tracking would be greatly appreciated! Thanks in advance :)