Congratulations on your weight loss!!! It is no easy feat, as I know all too well! melissalynn said exactly what I came here to say. Artificial sweeteners are not good for anyone, but they can hinder efforts to conceive, since that is what you're asking. They might be extremely low in calories, but your body is still processing them as sugars, and it's messing with your system in other ways (like telling your body to crave more sweetener, making a sugar addict even more addicted to sweet things). I'm on my fifth pregnancy right now, and I haven't exposed any of my babies to artificial sweeteners. Instead, 6 1/2 years ago when I first started TTC, I decided I'd train my body to enjoy things less sweet. I lost 60 pounds while TTC my first, and cutting way down on real sugar was a huge part of it. I enjoy coffee at least once per day, often two or three cups of decaf a day, adding a small amount of (homemade) creamer with real sugar instead of the large amount I used to use. Some people like Stevia, but I can only handle a very teeny amount of it. I will put a tiny bit in my iced tea and also use a little bit of real sugar, so I can't taste the stevia. I won't buy anything made with stevia because I always think it tastes like stevia. Yuck. My kids like the taste of stevia, though. (This is real stevia, not Trulia or any of that garbage.) Most people can handle xylitol, and I think it tastes just like sugar, but that's not always a safe bet, either, as it can cause tummy trouble in some people (or in large amounts), and it's commonly made of corn, which some bodies can't handle. You could buy a small amount of non-GMO xylitol and see how you like it, though, if you're looking for another alternative.
I have PCOS and insulin resistance as a result, so sugar is something I need to be very careful with. I conceived three of my babies at the tail end of, or directly after, a Whole30 plan. I've used it to help get rid of my sugar addiction and food problems, never to conceive a baby, but feel free to research it. Since I've gotten pregnant after/during it so many times, I recommend it all the time to people who are TTC, and it has helped many of them conceive as well.