You could be charged with possession of a controlled substance or possession of a small amount of marijuana. If you are a frist time offender you could be eligible for a diversionary program such as ARD, of course you may have some valid defenses and they should be expolred by counsel before you make a decision on how to proceed. Sometimes it can take several months for charges to be filed especially if the police are awaiting lab results on the substance they found on your person or in your room. Also if you gave the police your drivers license with a home addresss rather than your college address the citation or complaint may have been mailed to your home address so you need to have someone look out for that paper work.
This information does not create an attorney /client relationship and should not be use or relied upon to make any decision in your case. Only consultation with your own attorney can provide you with the advice you need for your case.
If the amount of pot was under 30 grams, you may be charged with possession of a small amount for the drugs. You may also be charged with one count of possession of drug paraphernalia for the pipe. Both offenses are unclassified misdemeanors. Potentially, you could have a conviction to a drug offense on your criminal record. A conviction for a drug offense may affect your ability to get student loans or other government assistance. I don't find it unusual that you you have not heard from the police yet. It takes time for the crime lab to complete the testing. In this case, I highly recommend that you retain a criminal lawyer to contact the police officer, and try to negotiate a favorable resolution before the charges are filed with the court. There is no guarantee that this will work, but you don't know until you try. Good luck.