Mama, please see your doctor or go to the clinic as soon as you can, kahit mahina lang ang dugo, better safe than sorry lalo na fresh pa lang you from birth, especially with intercourse involved. Hindi kami pwedeng sabihin kung normal lang yan or something else, pero yung OB mo lang talaga ang makakasiguro, at important na malaman ninyo agad. Four weeks postpartum at may changes sa bleeding after activity, deserve mo ng professional check, hindi lang online reassurance!