starting to feel werid...

Hi,
Welcome to ehealthforum,
If pre-cum or semen has come in contact with vagina, pregnancy can result (the chances are high especially if you were during your fertile days/ovulation time at the time of the sexual contact). Do not depend on the appearance of symptoms alone as indication for pregnancy. The appearance of symptoms depends on how your body reacts to the changing hormonal status. Few women can experience symptoms as early as 24 hours after fruitful intercourse. Few women can experience few symptoms after having missed periods. Few women do not experience any symptoms throughout pregnancy. The symptoms that you describe could suggest possibility of pregnancy (or ovulation cramps if you are closer to time of ovulation). Look out for development of any other new symptoms if pregnancy is suspected. Wait and watch for your periods. If you do not get your periods within 10 days of expected period dates, or if you develop any new symptoms, or if you suspect chances of pregnancy, you should consider visiting your doctor/gynecologist for thorough examination (to confirm pregnancy related changes/signs in body) and blood/serum HCG level test (to confirm/rule out pregnancy accurately).
If pregnancy gets ruled out, and if you are not ready for pregnancy, but 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. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest.
Take care.