Trying to conceive

Halli
Ive been TTC for a little over a month now. Im not sure if its because my periods are irregular, my last menstrual cycle was in January and Thankfully I just started my menstrual cycle this month on April 19 and tomorrow makes day 4 of being on it . I was wondering if you can still get pregnant if you have irregular periods? Also , when are you most fertile or ovulating after your menstrual cycle?