I did a HPT 4 days past when AF was due and the result line was darker than the control line!!

And yes I'm having twins. So maybe you are too??

ETA: I didn't find out I was having twins until my nuchal scan at 13w1d. I'd previously seen the OB who palpated my tummy (only in one spot) so only found one heart beat. You can imagine my shock at the scan - where I was by myself!!!