What if I was pregnant the whole time?!

So here I am on CD 37 with a LP of 21 according to my chart anyway.  I dont even know if I O'ed this month at all.  I didnt see any signs of it.  Anyway I was on progesterone this month for 14 days.  My normal cycle is about 28-30 day with only 11 day LP.  So I have been expecting my period for about a week now.  I have been patient though since I figured with the progesterone things would be different.  I called my Dr to let him know my concerns and frustration and am just waiting to hear back.  If I could find my pregnancy test that I know I have somewhere I would have taken it by now.  My breasts hurt not quite as bad as when I was preg with my son but since I dont normally get that with my period its kinda wierd for me.  I assume again its from the progesterone.  If I had conceived on nov 9th when I did my first IUI I'd be 12 weeks along and I have a hard time believing that is possible without me or my dr knowing it.  I had U/S's at 4 weeks and 9 weeks looking for good follies with no luck.  But as far as I know we never saw a baby either! Im SURE he woulda told me if he had! lol.  I looked online today and heard that at that early time its possible not to see it yet.  And I do have a little tilt to my uterus, so I have been told.  So here I am with 3 cycles since the IUI that are all not normal.  Before the IUI they were normal.  Why would the IUI have changed that if im not preg?  FRUSTRATED!!!!!  So now here I am with brown spotting again for the last 2 days expecting to start bleeding any minute.  I am supposed to start Clomid on CD5 but I have no clue how Im going to tell what cycle day it is if it doesnt turn red.  Im so scared about wasting this cycle all together cuz Im gonna miss it.  They say the first day of your cycle is the first day of red blood.  what if i dont get red blood.  The brown blood is old blood right so I dont actually have a period yet then right?  On the first even of spotting there was a couple pink spots in it but thats it no sight of that since.  I gotta quit talking Im asking all these questions no one is answering so I should just quit for now before I upset myself.