Just a quick update. While I was at the Dr's she gave me a slip for a BT and said to get it done when AF is due.
On the way home we had to pop down to Coles and I couldn't resist going and getting a First response test (beema's suggestion ) and couldn't help myself so PAOS when I got home. Anyway got another super faint light pink line, and this was within the 3 minutes so def. not an evap line.

I'm that the lines keep getting darker over the next few days and praying for a sticky one