Is spotting a sign of pregnancy before its time to start your actual period?

It can be. It can also be your period coming. It's hard to tell for sure.

Implantation bleeding which is actually quite rare usually happens about 8-10 days after ovulation. Some people bleed when they would normally be getting there period if they are pregnant. Usually both types of bleeding are a lot lighter than a usual period.

Also as Charlotte says a lot of women spot for 1 or 2 days before they get there periods.

Are you trying for a baby and if so are you late for your period yet?