Shorter time in between periods mean shorter luteal phase?

My periods are 24 days or less, does that mean my luteal phase would be shorter making it harder to get pregnant? I get cramps all of the time sometimes with nausea my doctor said it's something some women have with ovulation and that the only things to take it away is either get pregnant or go on the pill. I got my implanon out January after 2 1/2 years.