How Long Does It Take For Meth To Get Out Of Fetus S System?

How long does it take meth to get out of the fetus system and sense I will not be doing any drugs again after reading all the effect. .will this still show in the drug test they do on the baby in 4 months when he is born? I have probably smoke it 3 Times the month of February And once the beginning of March before I looked in to everything in detail. Each time I smoked it was not very much..maybe 4 hits (smokeing) each day that I had smoked it. So my questions is 1) how long does it take meth to leave The unborn baby s system? 2) will this show up on The baby s drug test at birth in 4 month even though I will not be doing it again?