clear blues can give you a reading about 4 days before a missed period but it wont always show up positive. i used the tescos pregnancy tests you get two in a pack and they are cheaper then one clear blue.... when i started using the tesco one it was only coming up with a faint line (so must have only been very early in pregnancy)...but three days after i took them i used a clear blue just to make sure.
if i was you just to be on the safe side if stop using your pill and use condoms insted until you know for sure because the pill might not be safe for the baby (if there is one).
do you normaly have iregular bleeds or is that just a one off? because it could have been impantation bleed. if you go to the doctors he/she might be able to offer you a blood test to see what your hormone levels are...i think they can tell you sooner then a home pregnancy test.
chelle,lilly(8months)&21week bump xx