In general it takes 2-8 weeks for you to feel the result of any anti-depressant. Your body is adjusting to more serotonin (makes you happy) in your brain, and you might be sleepy at first when you are adjusting. The first couple weeks is when you're going to have the most side effects.
I am by no means a doctor, so don't take this over medical advice, it's just my general knowledge from psychology.
If you have any extremely bad symptoms or signs of an allergic reaction contact your doctor or psychiatrist. Also if you are feeling suicidal.
I hope this info helps, and I hope you'll be feeling better soon