Yo! question on nutes??(N-P-k)

I just have a question about nutes. I heard during the flowering stage your suppose to give nutes high in p content. My plant is in the 3rd week of flowering. I gave it miracle grow during the veg state(24-8-16). I live in a country without many options for plant food. The few products I have found here seem to be weak or not up to standard. I am a newbie and really dont know about nutes. Anyway the couple i have found are like 5-10-5 and 0-52-34. Are these ok to use? Or should I keep looking?Any help would be great~~

it would be best if you could get better food. where you from?. when you say you cannot get any nutes?. cannot you order food from internet?.