CM question

Okay so im new to this whole ordeal..i have 3 kids but never tracked my cycle and ovulation or anything like that. Well normally every month i can tell when i ovulate..my CM is a lot more and a lot thicker for a few days...well this month i didnt have that..it's pretty much been watery all week...can someone please tell me why it may be that way? Last time we had sex was 3 days before my period