blackhatwannabe,
most people get a haircut between every 3 weeks to a month. So if you get a haircut a day before Yom Tov, this year you can get one 33 days later (since Lag Be’omer is Sun., you can get one on Fri before), then again before shevu’os (shevu’ot).
So if you normally get a haircut once a month, you’re OK.
For people who get haircuts every 3 weeks, a size shorter than usual is normal. So if you’re a bangs guy, a little shorter; just not that nifty just-just haircut you may be used to – it won’t last you so long.
Hope that helped. If you have regular FFB questions, feel free to ask.