Trying for 2nd baby

Period regular doesn’t guarantee that you have ovulated every month regularly too. Sometimes there can be blood shedding only from the uterine lining but you may not have ovulated (egg release from follicle) If you’re really pressed for time due to age concerns, perhaps get fertility check for both yourself and husband just to eliminate any possibility of any cysts or fibroids or other unexpected factors arising. Also, make sure you do the deed every other day during your fertility window (usually 1 week from LH surge) to maximize chance of conception.