Is this implantation bleeding? am i pregnant?

i've got nausea and vomiting yesterday morning. i don't think it's related to pregnancy though because i think i was just hungry and what i vomited was mostly gastric secretions, and i was having hunger cramps. i'm irregular and still waiting for my period. my boyfriend and i had october 1 and october 7 (today's oct9). when i woke up this morning, i was spotting a little bit, and had put on a pantyliner. it's not getting heavier! it's too early for a pregnancy test. what do you think about this?