Buying an iPhone 5s and an iPad air on the next two months, am I late to the party?

Hello everyone!

I'm going to get my personal ID next month, which means i could get a job on Mcdonalds or something. I'm looking to save up for an iPhone 5S and an iPad air, but it seems that i'll have to save up for at least 2~3 months. Buying an iPhone on April~May is a waste of money? Or a new model will come a little bit after these months?

I'm sorry for my weird English. It is not my first language.

Thanks everyone!