AF returning?

I know that I should probably just wait & see but I thought I'd see what everyone else thought...
I'm still BFing my (almost) 1 year old DS and on the 10th August I had brown spotting (only once!) which I thought could have been implantation bleeding but got a BFN 2 weeks later. Today I've been having quite a lot of cramping on the left side & lower tummy, soor bbs & am so very tired! I'm thinking that maybe it was the beginning of AF returning & AF will be here in the next day or two.
What are your thoughts?

The trouble with those symptoms is that they could be AF on her way or you could be pregnant. I think you will just need to wait a few days and if she doesn't arrive get another HPT.

Thanks for your reply :)
I thought that too & its not impossible :) I might wait until the end of the week & see how things are then test

ETA: I couldn't wait until the end of the week so I took a test this afternoon (should have waited until the morning but knowing it was sitting there got the better of me) anyway, it was BFN! But even so would be really early so FMU would probably be best...