If you are talking about 5th degree drug possession, it's not a misdemeanor, It's a felony. Now if you received a stay of imposition of sentence whereby reducing it to a misdemeanor, expungement won't do you any good. If you received a stay of adjudication, then you can proceed with a statutory expungement.
The general rule is that a case that was decided against the accused, either with a guilty plea or a conviction, does not qualify for a statutory expungement under Minnesota Statutes Chapter 609A as currently written. The exceptions are certain juvenile cases, as well as certain first time drug offenses which were either dismissed after diversion without a plea, or resolved as a special statutory "stay of adjudication" under Minnesota Statutes Section 152.18. More at links below.
It sounds like your case probably started as a felony 5th Degree Controlled Substance Possession and you received a "stay of imposition," which has the effect of reducing your case to misdemeanor after probation. The law doesn't allow a conviction like this to be expunged easily. The court will find that this case was not "resolved in your favor" and that therefore you don't qualify for expungement under the Minnesota statutes. The court also has authority to expunge criminal records, but it's a tough road. There are no hard and fast timing rules for expungements. Generally, when you've been convicted of the crime, you might be best served waiting five or even ten years.
Do not rely on this information. This post does not create an attorney client relationship. Please contact me directly to receive formal legal advice regarding your situation.
Hello. Please review the other responses. You may want to confer privately with an attorney who may advise you on certain action steps you may be able to take now with the aim of improving your position.