i asked him about STD's he told me he was STD free.

Hi,
Welcome to ehealthforum,
Intercourse without condom increases your risk of getting STD infection. Men can remain asymptomatic even while having the infection. Look out for development of any new symptoms suggestive of STD. If you were during your fertile days/ovulation time at the time of your sexual contact, chances of pregnancy are also possible due to pre-cum as pullout/withdrawal method is associated with highest failures (pre-cum/pre-ejaculatory fluid is known to contain sperms and no man can be 100% sure that pre-cum/pre-ejaculatory fluid did not leak out during vaginal penetration). Wait and watch for your periods. Look out for development of any other new symptoms if pregnancy is suspected. If periods do not start within 10 days of expected period dates, or if you get abnormal periods, or if you suspect chances of pregnancy, consider visiting your doctor/gynecologist at the earliest for thorough examination (to confirm pregnancy related changes/signs in body) and blood/serum HCG level test (to confirm/rule out pregnancy accurately). Visit your doctor/gynecologist for further clarification and assistance.
Take care.