I have a few questions and I am very confused.

I have been tracking my period for some time now due to me stopping my birth control in 2015. And witnin the last year it has regulated for the most part as far as coming on time. Last month my period came earlier than it was supposed to and my period this month was predicted to come three days ago and instead came today. However I am not entirely certain that what i'm having is my period. I had sex last month and in January all within a few weeks of eachother. I have been having headaches, but have otherwise felt normal until today. Today there was bleeding and cramping which feel like my cycle, but there's also nausea, headaches, and a weird tast in my mouth as well. I don't know what to think anymore.