i too had my baby boy in March. the 5th to be exact. my first cycle came on the 21st of April. but in May, it came over a week late, and girl, I was scared out of my mind. so i would say that based on my experience, your cycle may not be quite regulated, but theres always that chance if your not on bc. good luck!
I would take a test. You could DEFINATELY be pregnant if you haven't been using birth control.