I’m on my first round of 50mg clomid. Last cycle I ovulated when my follicle was around 23mm CD 10/11.

I went in yesterday CD 11 and I have 1 follicle at 27mm. I’m going back in tomorrow for blood/another scan and a CM check. She said i will have ovulated by Friday. (CD 14) my lining is 9 and looks good they said. My OPKs are the lightest they have ever been.. not even close to a surge. Is this normal? (Usually the OPKs are accurate for me every other cycle). I heard clomid giving false positives but can I not surge on one and still ovulate? How much bigger can my follicle get?