Did I sin against my husband by not telling him when I was ovulating?

Question:

If you feel like you may have sinned against your spouse years ago, but they don’t know about it, do you have to tell them now? I feel like I should give the backstory because no, it’s not adultery.

We were going for our second baby and he wanted a boy and I wanted a girl. I had read about this possible method that could “supposedly” sway the sex of your baby based on the timing of intercourse. The closer to ovulation you had intercourse, the more likely it was to be a boy. Slightly further away from ovulation, more likely to be a girl. My husband also knew about this method, as we tried it with our first baby (we both wanted a boy first) but it didn’t work. With our second, he still wanted a boy but I wanted to give our daughter a sister. I decided I wanted to try out that method again for some reason, but since I was the only one keeping up with my ovulation, I didn’t tell him and he didn’t know what the timing was. And we ended up having a girl. I sort of feel silly because it very likely didn’t have anything whatsoever to do with that “method” since it didn’t even work the first time we tried, but maybe it did, and I still feel guilty because I didn’t let him know.

I’m still not sure if that was a sin or not but part of me feels like it was, and I have prayed for forgiveness. But do I also have to tell him what I did? We’re trying for our third now and we both want a boy this time, so it has been on my mind more.