DS won't sleep (long)

acute_jenn

I am at a total loss of what to do.  DS is almost 11 months.  He took a normal nap yesterday morning, but would not nap the rest of the day.  He was in his crib for an hour just whining and talking.  Last night he screamed for an hour and a half before finally crying himself to sleep.  I tried everything, and I just figured he was overtired.  Well he slept for 11 hours last night just fine...no waking up.  This morning we went about a normal day...except when it came time for nap he screamed again.  I went in after half an hour....calmed him down...the minute I put him in the crib...he screamed.  I know he needs a nap, so I just left the room.  It has been almost two hours....he has not been asleep.  He is playing in his crib, but he has not had a nap.  Anyone have any idea what I can do....this is not like him at all.  He is usually an incredible napper/sleeper. TIA