suspect a clog

Hello everyone, I just opened my pool yesterday and left my pool pump running all night and everything seemed fine until this morning. I think I have a clog or a blockage in my pipe which goes from the skimmer to my pump. Whats happening is the pump does not seem to want to build up pressure as it has air in the clear lid. I can't seem to get the air out. I've never had this problem before as I have had my in ground pool for 16 years. Anyone have any ideas how to clear a blockage. I try blowing air through it from the pump end with my wet dry vac and it didn't solve the problem. Or perhaps could it be something else to get the air out. The pump is bringing in water but its appears its not enough and surges. Any thoughts appreciated.