gave birth 3 months ago, no period had sex, spotting, cramps

hi pls help if u can

i gave birth 3 months ago, about a month ago i had sex but did not use contraception thinking it would be ok since my period had not started (im breast feeding aswell), now a month on i feel pregnant with all the classic symptoms and i had a slight bleed which was pinky red about a teaspoon amount . i also bled slightly a few days after sex aboyt a month ago, i took a hpt which was negative but im still experiencing the symptoms with period type cramps yet no period, is it possible i might be pregnant?