Will the use of cocaine be out of a fetus system when born if there is no use for 3 months?

Yes: Cocaine is usually out of the blood system in 4 days. However, cocaine use even if stopped can be harmfull to you and the baby as it can cause vasospasm even months after using.

Cocaine use: If cocaine was used during pregnancy, particularly during the first trimester, the fetus could have serious permanent damage. Cocaine is usually eliminated from the body within about 6 days, but the damage may already be done. Seek an evaluation by your OB immediately.