My menstrual cycle is always regular. every 28 days for 3 days. last month it was 2 days late and this month it came 10 days early.it is a normal flow?

Pregnancy/Normal: The first thing that needs to be ruled out if AT ALL possible is pregnancy. If it is a possibility do a home pregnancy test. This could be a pregnancy or a "chemical pregnancy". The other thing is that at 23 this is a common occurrence. If the flow was normal and this was a one time thing no worries. If your next period is abnormal this needs to be checked. Good luck and don't worry.