Brown discharge & painful nipples

M
On june2,2016 SO and i BD and he finished inside. Yesterday evening, when i went to pee i noticed some brown discharge i know it could be implantation bleeding. Yesterday we also BD he finished inside again, and when i went to pee there was some more brown discharge but not on the paper toilet but insied the toilet mix with my pee. My nipples & lower back also started to hurt yesterday morning. My question is, is it too early to know if its my period that its coming or if it's possible i could be expecting? I know the only way to know for sure is to take a test but i think is too soon to test. Can anyone give me any advice base on their experience?