Well like MissEm said it only counts as AF if it's red flow. However even though you can still get pg the spotting is not great news either. I spot for 4-5 days before AF and I'm doing a cd21 progesterone on Tuesday so will be interested to see how low it is. My acupuncturist has also targeted the spotting as something he wants to fix - he would prefer AF to start all at once.

Also wondering if you chart and if so what are your temps like late into your LP - if they're low sometimes that can indicate low progesterone too.

It's quite simple to get your GP to do a blood test like madB says, that way you can know for sure instead of just wondering or fretting - that drives me nuts! Good luck