Medications - when ttc?

I recently hurt my back which has resulted in very pain in lower back. Leaving me not being able to do much except lay flat or sit on a very firm chair with my new bestie the heat pack. My question is have been given brufen to take 3 times a day, after chemist strongest pain relief made me dizzy. Also have been given Valium for the night. How will that affect my chances of falling pregnant as this has happens in 2 wk wait! If do become pregnant what affect would it have? Sorry for the long read just over the pain