I had an unusually extremely heavy period last month then this month it was 2 days early and lighter than normal with clots like usual. am i pregnant?

Not likely: Just to be certain, do a pregnancy test.

Probably not: Regularly timed periods (not counting the amount of bleeding) are usually associated with not being pregnant. Pregnancy is associated with an absence of a period. Take a test, home pregnancy tests are very accurate if you're concerned and are sexually active. If you would like a more regular period, consider birth control as an option to help regulate.