Ok so me and this guy have being dating for about 4 weeks a short time but I'm 14 and that seems like an age

Any way I wanted to keep it a secret cause my parents don't know (their a bit on the strict side but in every other area of life with exeptions I listen to them but dating at 40 noway!)
He said OK so we hang out on the weekends etc.

Anyway he got a mobile like 3 days ago and we have been txting non stop

Now here's the prob my best mate whom I tell everything is a bit of a big mouth when it come to boy everything else it seems she can keep her mouth undercontrol

She got a hold of my phone and I didn't delete my messages!

I let the guy know and he was a tad concerned but her didn't say it I had to leave school early and the had the last to classes together!

What should I do or expect for that matter the guy hasn't called or text me but he only had a little credit?

First off, the whole secrecy thing is a bad idea. A better way to go about dating is to work on earning your parents trust. If you can show them how responsible you are (which right now you are showing the opposite) you'll earn their trust. When someone special comes along, if you have their trust then you should be able to introduce him to them and let him start earning their trust as well.
And second, if you didn't tell your friend what's going on yourself then she shouldn't be saying anything. And this is just in general. If someone has to snoop to find something out its probably none of their business. So if your friend brings it up you just need to be firm with her and tell her you don't want to talk about it and you expect her to keep her mouth shut about it too. If she respects you she should respect your wishes.