I am a bit confused.... I have been ttc for 2 months (so not long at all I know) and my my cycle is usually 28 days without fail. I am now on cd24 and have noticed spotting. I usually spot for 2 or 3 days (and count this as cd1) then af for 3 days so this has really thrown me. I know I am being neurotic so the main reason I am posting on here is so someone can tell me to get a grip 
I just wondered if anyone else has suddenly had a change in cycle for no apparent reason?! Thanks and sorry for the near pointless question!