Contraception Injection & Future Pregnancy: A Young Couple's Concerns

Question
date of last day of menstraul period - sunday 02 Oct.
age - 23(will  be 24 on the 21 Oct)
children - nil

Hi,
my name is Angie and i have recently got married.  my husband and i have spoken a lot about having a baby - but then we decided to wait.  we both want one, yet we wanted to wait a little as we wanted to have time to ourselves first before a baby comes along - so i agreed to get the contracpetive injection.  i went on tues and had the injection done and the nurse told us that we still werent safe for another 10 days.  after much contempaltion we decided we wanted to have a baby.  we have been active with no protection!  will having the injection effect the baby if i am now preganat or is this ok?  
other than that - i do smoke marijuana and was wondering what the effects of this would be to the baby?
please help me URGENTLY!
if the injection is going to effect the baby - i need to go and take the morning after pill...

thanks
Angie

Answer
If your last period started on October 2, you will not ovulate until October 15 and can ONLY become pregnant if you have unprotected sex on October 14,15,16, or 17. Since you got the DepoProvera shot on October 4, you probably will not ovulate on October 15 so you are probably safe this month. Since you did get your period on October 2, it is too early for you to conceive this month, and the shot will "kick in" in 10 days, so you have nothing to worry about.  Marijuana does not cause any birth defects and should not cause any danger to a preganncy or to the baby, when you become pregnant. We encourage you not to smoke anything during pregnancy, however.Even if you did become pregnant while taking the DepoProvera shots, it would not cause harm to the baby or to the pregnancy. Don't worry.