I have all pregnancy symptoms and was 10 days late on my period. i then had a 3 day 'period' which was dark and a light flow. could i be pregnant?

Yes. Get a PT: The short answer is "yes". The bleeding could have represented a threatened miscarriage.

No: If you had completely missed 1-2 months of cycles you should be concerned, otherwise, this is a normal variation in your cycle; however, you seem concerned about pregnancy: BC pills, condoms and a pelvic exam by a GYN IM or FP will get you straightened out.