I am trying to conceive and just got my period a week early with heavy bleeding and some clots. could this be a miscarriage?

Very early: This would be very early for a miscarriage. You are likely bleeding for some other reason. See your doctor for an assessment and likely US. He may also want to check some blood work including a thyroid panel. All the best in getting pregnant.

Not likely: The first sign of pregnancy is generally a missed period, not early bleeding. I would see your doctor. Early bleeding suggests not ovulating.

Theoretically: It would take a positive blood test for pregnancy to confirm, otherwise it is a early period