If you have talking with client about 3 months, you do not get the order. Pleasedon't worry. I am sure you will have chance to make coopereation with them again,if your have showed your sincere to your client.
3 mouths makes you know more about your client , and your client can not forget you easily. But if you have talked 3month but not get an order , you need to find the reason why you can not get the order. i am not sure one client can talk with many supplyers during 3months.
So longer time taking with you client , more chance you will have. To be a successful seller you must be patient.