Can having a heavy period last month make this months late?

It is unlikely that having a heavy period last month would cause your period to be late this month. The menstrual cycle is regulated by hormones, and while there can be some variation in cycle length, a heavy period should not directly affect when your next period starts.

If your period is more than a week late, it's a good idea to take a pregnancy test to rule out the possibility of pregnancy. If the test is negative, you may want to talk to your doctor to discuss other possible causes for your late period.