I can understand your concern. A lot of factors can be responsible for the delay in your menses. The chances of you being pregnant are low considering that you used a condom during intercourse however the only way to be sure whether or not you are pregnant is by doing a urine pregnancy
test which you can easily do with the pregnancy kit at home. It is pretty accurate when performed correctly and after so many days of a missed period. Stress
can lead to delayed periods and so you need to stop worrying and get the pregnancy test done soon to rule out and then go ahead to find out the exact cause of your problem by visiting a gynaecologist. You may need to undergo some blood tests and ultrasound
to to find the cause of your delayed periods if pregnancy test comes out to be negative (which most likely it will). So dont get stressed and go ahead and do the urine pregnancy test.
Hope this helps.