Could Light Vaginal Bleeding Indicate Pregnancy?

my boyfriend came tolive with me on june2nd i was on my peiord i came off like the 3rd i think when i was on it we had sex and then after that .when he was here we had sex every single night but missed 4 nights with out sex when he went back on june 19th on my 19th birthday a day later being june 20th i was lightly bleeding and stop that night then came back then next day then stop could i be pregnate