I've been having period like cramps for 3 days. on nov. 22nd, i bled a heavy reddish brown color for 2days before it turned light pink for another 2 days then completely stopped, i don't know if it was implantation bleeding or a weird period?

A person can't tell: A positive pregnancy test can tell a woman that PRIOR spotting was actually implantation spotting. Until then, it can be hard to tell if a woman is pregnant because some symptoms seen in early pregnancy can also happen in non-pregnant women. A urine pregnancy test gives a reliable result about 3 weeks after sex (3 weeks after when conception might have occurred), or 1 week after missing a period.