The cervix is usually more friable (i.e easier to make bleed) if you are pregnant. However, bleeding after sex can also be caused by cervicitis (cervical infections) or abnormalities to the cells which line the cervix (which can be caught by a pap smear).
You should get a pregnancy test. Even if you were pregnant, doing the cervical test will not trigger a miscarriage. These tests are routinely done on pregnant women at their first OB visit.
Thanks!
First step. get a quantitative blood pregnancy test. This can be followed every 2 days or so until it gets to a level at which the pregnancy can be seen by ultrasound. Bleeding in early pregnancy usually gets worked up in this way. In the process, have your ob/gyn check the results of the cervical test and do the appropriate therapy.
The majority of bleeding in early pregnancy does not lead to miscarriage.