About a week ago I punctured my front inner tube when I rode over some bryers or something with a sharp point. I went to Wal mart and got a patch kit and patched the hole which was needle sized and it slowed the leak down and it took about 3 days for all the air to leak out. A few days later I pumped the tire up and it held air for a long time while I was riding it. The next day I went to ride it and all the air was out of it. I pumped the tire back up and rode to my freinds house which is only a quarter mile away and sat the bike down and talked for 5 minutes and the tube was completely flat. The funny thing is that after I patched it i didn't ride over anything but asphalt. What should I do?