It depends on the half life of the drug. What you could do is, call your dr( the one who put you on the drug, or even better, call a OB/GYN..tell them you are thinking of having a baby and this is what medicine you are on..etc.). or call the emergency room and ask a nurse or a dr. Tell them what drug your on and they should be able to either tell you off the bat, or at least look it up in a medical/drug book, and give you an idea. That would be my advice. An OB/GYN would probably be the best place to call to get info on that. :) Take care and God bless!
In His Grip,
'I do not ask the wounded person how he feels, I myself become the wounded person.' ....Walt Witman
"Bear one another's burdens, and thus fulfill the law of Christ.".....Galatians 6:2