Can you please help me?

Question
So everybody is saying that guppies are very easy to breed, and I know myself that it is very true. But I have this beautiful pair of them for almost one year now but they haven't breed once! I know that the female hasn't got a breeding problem because she was pregnant when I bought her and she had three frys a week later. My male always chase her around and is showing obvious signs of wanting to mate. So can you please try to explain why is this? Thank you for your time and I'm sorry for any inconvinience!

Answer
is your temperature up to about 78-80 degrees farenheit? hotter temperatures help with breeding.

also, feeding brine shrimp might help them get in the mood to breed.

You are sure one is male and one is female, right? im guessing you are, just checking.

you might want to buy another male and maybe two or three more females. The more there are, the more likely they are to breed. The only down-side is you can't really be sure which ones fathered which babies, and if you don't put the mother in a breeder net then you can't even be sure who the mother is. If you aren't worried about knowing which ones parented which, then this method will probably work for you.
First try the temp. raise and the brine shrimp though, this always works for me. If not, then try buying more guppies. The male could be sterile, but you can't just buy one male becuase you don't want more males than females, this stressing females out becuase they are constantly chased and males might fight each other if there aren't enough females to go around. have at least one female per male, but two females per male works even better.

i hope this helps you out and you get some successful litters in the near future!!
ps. sorry this took a long time to answer, ive been having pc issues.
best wishes, chelsey