MC confusion

In Aug(2012)  I had a tubal reversal and my period became regular right away after surgery and has always stayed regular. I was supposed to get AF on Dec 5 but ended up missing my period.  I had a mc on Dec. 9/10....I am guessing it was a natural mc because i tested + on hpt..then slowly it faded to a negative.  I had gone to my ob/gyn and they did blood work to confirm but after i started bleeding like a normal period and called them they told me to just keep a watch on my temp and if i had any pain...and since i was only 5 weeks at the most to just let it happen naturally...well i started bleeding on dec 9/10 it lasted for about 5 day and then nothing...i figured was good to go...about 2 weeks later i felt my body ovulating...my husband and i did get together at that time but only once since i was a little scared and now i am late by 4 days....i took hpt and they have all come back neg...has this happen to anyone and should i wait till next week to see if i get my period or test positive?....with me having the reversal my chances of having a tubal pregnancy are higher...