Hi Dear,
As you told you were on pills for birth control, one of the very effective method of birth control, the spotting which you are experiencing may be just normal and will ultimately lead to your periods as you have stopped the pills
The endometrial thickness varies through out the cycle with 11mm in later half of cycle being absolutely normal.
Also if you had sex during your safe period i.e roughly after 18-20 day of cycle
than chances of pregnancy are less.
But even pills have a reported failure rate of about .5-1%, so there is no harm in doing a pregnancy test
All the best

Hi,

Based on the information it seems that you just stopped oral birth control pill and had sex after that, as well as you endometrium thickness is 11mm on ultrasound, and wanting to know if you may be pregnant since you have not had full blow period and just spotting.

The answer to that question is sometimes it happens that spotting occurs to women coming off of birth control pill.

Here are two thing that can answer for sure wether you are pregnant or not for sure.
1) Wait for a week till you get a full blown period. It some times messes up the normal cycle.
2) If no bleeding, then take a over the counter urine pregnancy test (where you have to pee on the stick to find out wether you are pregnant or not) do it after 15 days from now, if negative first time take same test after a week i.e 21 days from now and confirm it.

Hope it helps,
Thanks
Dr.JAY PATEL.