<<...I just got my tablet a little while ago...>>
...By any chance, did you buy the tablet new? It sounds like the nib (the white plastic tip) has simply fallen out of the pen. If you got the accessories that normally accompany any tablet, you should have a pack of 5 replacement nibs somewhere. Simply take one and re-insert it into the pen. Press it gently but firmly to "seat" it. Then you should be good to go again.
If you didn't get a pack of replacement nibs, you can get them from Wacom or HP for a very nominal price. Search for "replacement nib"