Do Pregnancy tests only work from day AF is due or can you test before?

[northerner]

Or am I being really stupid?

Did the deed on fertile days and want to know but AF not due till end of this month.

Thanks guys!

you can tell from a few days before period

I seriously would wait though

just think how you'll feel if you test + and then your AF arrives

that was my fear anyway

You can do them 3/4 days before.

My af vary from 24-29 days. I tested on day 24 which gave me a BFN, tested on day 28 and got a BFP.

OK, thanks. AF is due 28-30 December. So a bit too early now then!