rubbing our genitals against each other and...

Hi,
Welcome to ehealthforum,
If during your sexual contact, pre-cum or semen has come in direct contact with vagina, pregnancy can result. Hymen has passages in it that allows for menstrual blood to pass through and through these gaps/passages, sperms can also swim up towards uterus and tubes to fertilize the egg (if it is present in your system around the time of your sexual contact). Oral sex alone does not result in pregnancy as there is no direct contact of semen with vagina. Few women can get period like bleeding (decidual bleed) during first few months of pregnancy. If you get abnormal periods, or if you develop any new symptom suggestive of pregnancy, you should consider visiting your gynecologist for further evaluation and assistance. Take adequate rest. Drink plenty of water. Maintain healthy diet. Be in regular follow-up and monitoring of your treating gynecologist/obstetrician and report any unusual/abnormal/new symptoms immediately.
If pregnancy gets ruled out, and if you intend to remain sexually active, consider visiting your gynecologist to get started on suitable regular birth control measures to be protected (after your periods). Be regular with birth control use as instructed. Avoid having unprotected sexual contact.
Take care.