I could never keep up with my cycles, they were so irregular. I would go easily 3-5 months at a time without getting one and then i would have maybe 2 in a row and then again months before my next. They then started to get very light and lasting alot longer, i had one for 21 days. That was the last one before the one i had in October, that one was a normal one. That was i think the first after being on the pill and metformin for about 3 months. It lasted my usual 5 days. I didn't expect to ovulate at all that month so when we DTD 10 days after and we didn't pull out as we usually do... i fell pregnant.

It was such a huge surprise. So i don't think having longer cycles has any affect..

Goodluck