Lucy - AF stands fro Aunt Flo (period) on this site. .. somewhere there is a list of all the abbreviations that I read.
I have not used ovulation sticks, but I will tell you what I know about the CBFM so you can compare.
CBFM is about £55 on amazon. Then you need sticks each month - £13 for 20 (amazon). You use it every day of cycle, but only 10 or 20 sticks each cycle depending on how long your cycle is. The first month you press the button on it as soon as period starts (day 1 of cycle), then around day 6 it asks you to use a stick, put it in machine and it records whether it is a LOW, HIGH or PEAK day. Recommended to bd on High and Peak days.
I used 20 sticks the first cycle, as it learnt about me and now use 10 sticks (a 28-31 day cycle). For me benefits are: I always know what day of my cycle I am on, I can target bd, ensure not miss important days etc, taken stress out for me (not saying it will work though!!)
Yes, it is expensive - then I thought "how much is a baby worth to me?" 12 months just ttc, no costs - now throwing everything at it (got to be cheaper than fertility treatment and worth a shot): so CBFM and its sticks, pre-seed, now softcups (temping will be next I guess!)
I thought about what I spent on other things and changed priorities. But that is me, my story. I guess if you get a machine and it works you can sell on ebay and recoup some cost??
Keziah