If you were expecting AF on March 28th that means you're 2 weeks late. Depending on when you ovulated you could actually be 2 weeks late and that would me you must be pregnant OR you only just ovulated a week or so ago and your AF will be here on time.
After you ovulate, it's called the luteal phase. A normal luteal phase is (I think) 10-16 days or something like that........although I have had 18 day luteal phases. Anyway, this phase length doesn't usually fluctuate like the follicular phase (the phase of your cycle before ovulation). Stress and who knows what else can cause your body to delay ovulation making your AF late.
It's possible that you are pregnant but that you may have ovulated later than usual, making it too soon to tell. And of course there are those sort of rare cases where women that are pg don't show up positive on the tests.
Are your cycles usually regular? Have you had this happen before where your AF was really late?
TTC makes us all crazy! You're among friends
New to board
silly ticker you should say "weight gained" not "weight loss" 
for one last miracle baby
