Can some help me please?

Lisa • Married 5 years to a wonderful man. Son born 26 Jan 15. Expecting another boy in Nov 16 X
Im trying not to worry but I have started to...
​First month using Glow - I'm on CD 19 and normally I'm 30-33 day girl.
​I started using OPK on 12 and all negative. My CM is now watery but no stretch.
​I'm worried I'm not ovulating.
​I bought some clearblue digital OPK to compare to the cheap ones - still negative.
​I have just told Glow I have used clearblue these last 3 days rather than 'other' OPK and now it's pushed my fertility window back by 3 days. 
​Glow thought my most fertile day was yesterday. I have no O system eg tenders breasts or nagging pains in sides which I know I have experienced in the past
​If I do ovulate very late, does this mean by lutal phase will be too short to convcieve? 
​I know worrying won't help and I said wouldn't get worried but I think I am. Sorry for so many questions
​Anyone got any advice or thoughts?
​Thank you ladies xxx