Honestly, yan ang tricky part kasi parang both things pwedeng mangyari, pahabol na menstruation or implantation bleeding, especially if may intercourse involved! A few of us mums sa group namin nag-usap about similar situations, at iba-iba talaga ang experience. The safest move talaga is to take a pregnancy test after a week or so, or check with your OB kung medyo worried ka na, kasi sila lang talaga makakasabi ng tama based sa your cycle at tests. Good luck, sis!