Omg could this be it? Dont want to get my hopes up!

sooo I am only 4 DPO, woke up with not only a tasting like there was a penny in my mouth but I swear I smelt it too. Slight twinges in my pelvis at night and my boobs hurt so bad I can only wear a sports bra. The boobs I can understand I think it's normal this part of my cycle not usually this bad. The penny taste in my mouth.. wierd?? Not to mention this massive headache. Anyone experience anything like this, this soon?