Hello,
Thanks for your query at DoctorSpring.com
I have gone through your question in detail and I can understand what you are going through.
Three things to consider:
1) You were regularly on Diane 35 (OCPs) and you took the missed dose with in 12 hours. That helps in maintaining the blood levels of the OCP.
2) The penis was inserted only half way through and that too half an hour after ejaculation. This minimizes the chances of getting pregnant.
3) You have tested for pregnancy thrice with the last one being 8 days after the day of missed period.
That makes the chances of you being pregnant almost impossible. You need not worry and further and you need not do any further tests.
But try to be more careful in future. Do make your boyfriend use a condom. It helps in saving you from unwanted pregnancy and also from various sexually transmitted diseases.
Hope this helps,
In case if you have any further query, do let me know.
Kind regards
Dr. Srikanth Reddy

There are plenty of reasons for a delayed period. Stress, anxiety and being sexually active are few of them. You may still wait for 10 more days and if not then an uktrasound of abdomen may be required.

Regards
Dr. Srikanth Reddy MD

Yes that makes sense.
Primolute will help in reducing the frequent cramping.
If you want further advise, you can initiate a new query under our gynecologist and she can help you further.
Regards.