10 days ago i took ec (2dpo)dark brown bleed 6days after & very mild cramps. now strange butterflies feelings and mild nausea.can i still be pregnant?

Unlikely but: It is still possible. The symptoms you describe are common after use of emergency contraception. Though it is a bit prolonged, it still wouldn't be out of the range of normal. It would be borderline early to test with a home pregnancy test but not unreasonable. Even if it's negative consider repeat testing in 4-7 days to make sure. If your symptoms persist see your doctor.