Good afternoon!
I'd encourage you to look at websites like this one,
http://www.christiandomesticdiscipline.com/ (I believe it may have even been used before here on another thread) that address discipline in Christian marriages. There are many out there on the internet, so through careful filtering (as to avoid the weird and sinful BDSM type sites) you can find some very helpful tools. I found this one within a few minutes of reading your post.
I can also offer up advice that comes from my own marriage. Though my marriage is in a rocky spot right now we had 19 years of a healthy Christian marriage previously.
Now I’m aware all marriages have their different dynamics and what have you so some may disagree with what I’m about to say. My wife was a little slow to catch on at first so in my marriage I found the use of physical discipline being administered was not unlike getting into a pool. Sure you can dip your toe in, test the waters, but it is best if you just dive right in. As a good and loving husband I had a rule that I would give my wife one verbal warning before resorting to having to correct her through physical means. This way if she does it again she has no one to blame but herself. She is practically making you do it! Assuming your wife is a good Christian woman she will understand and in fact be grateful to you for making her into a better woman.
A perfect example, my wife used to be awful about telling me to do things like take out the trash. Every time I’d be walking out the door to go to work I’d hear her calling out from whatever part of the house she was cleaning for me to take out the trash. I reminded her of 1 Timothy 2:12 and also that cleaning was her responsibility and told her that if she forgot her place again... Well, I’d have to remind her in a more serious way. So my wife had just had gotten home after going through a difficult 72 hours of labor giving birth to our first son and for some reason was finding it difficult to perform her womanly duties around the house. Sure enough, she told me to take out the trash. Staying true to my word I resorted to a little physical discipline, and let me tell you not only has she never brought up the trash again she was even grateful for the lesson! Sure, I could have just taken out the trash as I was walking out to my car. The trash bin is about four feet away from it, but if I had done that she would have never understood or learned her lesson. I do not have to resort to physical discipline often but when I do my wife never makes the same mistake again.
Have you searched the house for these anti-baby pills? Perhaps even taken her to a Christian doctor for a drug test? If you fear your wife is taking these pills and do not trust her word then perhaps it is time you get proof, one way or another.
I will pray for you to soon be blessed with a son.
YIC
Chuck