Implantation blood or menstrual blood

I noticed today while wiping that there was some blood on the paper. I haven't had a period in over 2 years due to a pregnancy, breastfeeding and being on birth control. I recently stopped taking my birth control and dont know if this is just my period finally coming along or if its implantaion bleeding. My husband and I had sex last week and im not sure how implantaion bleeding works because when It happened during my first pregnancy I thought it was my period. Can anyone give me some insite?