So far my understanding about withholding, most of the time state withholding are enough for your state tax liability unless there are other things. Accordingly for each state you work would be sufficient withholding for tax liability.
I may have to look MD's tax practices, if you reside MD and your earning in any state will be earning of MD may make you pay taxes because you have not enough holding for MD tax. But most of the case it will ask how many days you stayed on each state and earnings from each state.
If it shows you owe to MD, I suggest to clear it out. You do not want a mess to be carried forward too  long.  You will end up interest and may be penalty?

I have suggestion, as I did to others. March is lousiest month for tax season. Visit to nearest H and R Block tax station. They will put all info and give you the numbers you will be receiving from Federal as well form State. Do not hesitate to walk out because you do not have to pay dime until filed. Just a wild guess, you may have omitted some info that is leading you to pay in MD or you may be right unless we redo and check if numbers are correct. 
If you give me the numbers ( couple buck up or down, no ss, no name but state and zip code)
Exactly they are in box 1,2, 12, 16,17 and date you stayed in each state. Any other income and deductible you have claimed. Email me I will run number for you and will tell you if you owe to MD or not.