Hi Raees,
You have nothing to worry about after only 3 proposals. It normally takes much more to get a project, especially in the beginning when your profile has no history and no feedbacks. Even freelancers who have a strong and developed profile don't always land every 3rd job.
I'd say you shouldn't worry until you've got let's say 20-25 unanswered proposals. Just make sure your cover letters are good and tailored to each of the jobs. Sooner or later, you'll get a reply 🙂
