OPK and BBT

Tulips26
I started doing opk the day after my period ended. I'm now on cycle day nine out of a total cycle length of 27 days. My Opks are very very faint. How long does it usually take to show a surge... My US and blood work is Saturday and if follicles size is good IUI will be scheduled Monday. 
Also I bought this CVS brand bbt thermometer and it's very unreliable and not working. Only had it for 4 days and it doesn't even recall the temp before when turning it on.  Do you guys rely greatly on those alone.. Please let me know your experiences. Feedback appreciated. I know some people ovulate late. My ovulation day is Saturday but I thought I'd see some increasing line. Pics attached 

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