I had my period Jan 17 and I inseminated jan 26th... my periods always come between 24 and 28 days per month... I have 2 other women who live with me and all our periods come in the same week days apart... last week Feb 6th I had light bleeding ranging from pink, bright red to brown for 4 days my period wasn't scheduled until between Feb 10th and tomorrow the 13th. I have had some light cramping heavy breasts sensitive nipples and some nausea... sometimes I have pain only on the my side... I don't know what's going on. I don't take birth control I'm not sexually active with men. No infections and no stress... I took a hpt on Feb 7th and Feb 10th both negative...

Based on your dates, you had sex during what COULD have been your fertile period. Periods are unreliable though and can change. That being said, the bleeding you described is not implantation bleeding. Implantation bleeding is rare and when it does occur, it's a few spots, never lasting more than a day or two at the absolute most and not brown (which is old blood flushing out).

Try testing again in a week using first morning urine. If you have any doubt, you could get a blood test to confirm.