Too soon???

So ... my last cycle ended July 27th. I'm supposed to be starting this week with my period. Sunday I had a large amount of red blood and now little to no discharge. I am bloated and feel gassy and I have been nauseous the last two days. I've seen nothing that resembles implantation. My boyfriend and I have not had any penetration but I am super stressed about this and some other things. Should I just give it a week or should I be testing? This is all very new to me and I'm kind of in the dark on this.