What kind of opk do you use/like?

Melanie • Rainbow baby girl conceived with the help of science and born 5/23/17, pregnant with baby number 2, due August 29th
I have been using the clear blue advanced digital ovulation tests. Since I had a MC in December, my cycles have been off and longer. I have been getting weird results from the digital ones, like peak fertility abs low fertility alternating for almost 2 weeks. Have any of you switched from these to the cheaper ones? Thoughts? Anyone had a lot of success? Like pregnancy after MC, or pregnant very quickly?