My period dates are 12/1, 2/2, 25/2 are these regular/irregular and if not is this a problem for not conceiving?

Can be problem: Your cycle length is 20-23 days. When woman have a cycle this short it is possible there is no ovulation or there is ovulation but the Progesterone hormone isn't high enough to get pregnant easily. A work up for this can include using an ovulation predictor and checking a Progesterone level.

Shorter length: Your cycle seams to be regular but shorter than normal cycle length that is 28-35 days, shorter cycle means there could be a problem with ovulation because. See a doctor sometimes it can be fixed easily with weight loss and contraceptive pills. Wish you all the best.