Kylie, different HPT's detect different Levels of pgcy hormone and so it is entirely possible that you are pg, but the -ve one wasn't sensitive enough to pick up the level you are at atm. Give it a few days and do another test (line should be darker) or go for a BT (these are MUCH more reliable, however have been wrong on occasion also due to levels being too low at the time). Some people produce heaps of HGC right from implantation, others (like myself) take longer (I never get +ve HPT's till I am min 10days late). You're cycle being irregular makes it harder for you, so a BT would be your best chance at a reliable answer and failing that, an u/s. Maybe talk to ur Dr about testing all hormones at the same time so if it does come back BFN (which I HIGHLY doubt) you may be able to tell if you approx where in ur cycle u r at... I personally think ur UTD and wish you goodluck (not that u'll need it soon to be mum!). I hope everything comes back BFP and you have a happy healthy pgcy!