Period or implantation?

So I've been feeling nauseous and my period is about to start in 4 days well that's what eve says . But , today I had two dots of light brown spots and it was watery ..... I have never in my life have had that .... and to let you guys knows I've had unprotected sex too . It's been about two weeks since. I've been cramping as well and got a bad lower left back pain .... coukd I possibly be pregnant ?? I'm excited if I am ! I'm not home right now to take a test I'm away on vacation so I kinda want to get some advice ! Please !:)