I am 3 months pregnant and I have a cold, which medicines can I take?

?symptoms? Depends on what symptoms you're having. Mostly a cold (upper respiratory/viral infection) improves with time, rest, hydration. Steam or mist may help (think humidifier, warm shower, soups, tea). Check with your OB if you feel like you still need medication despite doing those things. Don't smoke or be around second-hand smoke. Feel better.
Pregnant w/ URI. I would check with your ob/gyn to confirm what if any medicines you are able to take, based on your most bothersome cold symptom. Often nasal saline spray or rinse will help.