Oh gosh I'm sorry I only just now saw this!
1)It's ok to only use RepHresh a couple times or even once. Yes you can combine Sylk nd RepHresh, they are said to complement each other and
2)I always recommend one attempt at peak and since you'd been doing cutoff, I'd like to see you have at least 1-2 months with one attempt at peak before adding attempts.
3)Whatever you did was the right thing to do, but if this ever happens again, what my rule of thumb is in this scenario is that for best odds of pink, stick with the attempt you've had, for better chance conception, add attempt. I typically have you guys stick with the attempt if you get the pos OPK within 2 days, add attempt if it's four days or more later, and in the 3 day zone, go with whichever option is more important - pink or conceiving.
So I would have had you stick with the attempt you'd had, but it is not a dealbreaker if you had another one.