I had a natural miscarriage in october. i have had normal cycles since. however this cycle is very heavy with a lot of clots. could this another misc?

Possibly : A pregnancy test would confirm if you are or were.

It's not: Impossible. You could check a pregnancy test in that if the pregnancy was far enough along to cause that issue, it may still be detectable. It is very unlikely, however, that this was the cause if u did not miss a period. Variations in the cycle can occur for multiple reasons, most will return to baseline. Gd luck.