Super light hardly there period?

Well, I'm sure this is just my paranoid self (my boyfriend is military and due to possibly deploy in January) so I get worried whenever something irregular than what is normal. Well usually my period lasts about 5-6 days, usually it starts about 2 days after I start the placebos of my birth control, it didn't start until day 5 then it was so light it was hardly there, like it only showed up for two days then nothing. I took a test but it said negative, I have felt kinda nauseous but no actual sickness. Anything helpful?