OPK Question

 I got my AF on 4/26. However, it was pretty light, which I read can be normal right after stopping BC. It lasted 3 days and I spotted on the 4th day. I starting using opk after AF ended and have mostly been using the dip stick Wondfo brand. Today I used Clear Blue Digital and got a happy face!!! Which means there was a surge. 😃  Can I be ready to ovulate this early in my cycle?? I also tested with the Wondfo brand a little later today and it did not detect a surge. Which is why I'm a little confused about what all this means. 

Also, I started using Fertilaid on 4/29. I don't know if this matters or not, but I thought I would include this information just in case.

The glow app says I'm not starting my fertile time until the 8th. But since I got that happy face with clear blue I started taking Guaifenesin today. I plan on taking it until the 13th, which is the time glow says I will be out of my fertile period. Do you think that is too long to take it?   

What should I make of this? Any comments would be greatly appreciated. Thank you in advance!