There is also the Flashbang option, for concealed carry. I had the original Flashbang model, but I had issues getting the mag well to lie flat against my core. Not sure if this was due to the bra, the holster or something else, but it just didn't work for me. Further experimentation is needed, but I sold the holster.
I did decide to purchase the "Marilyn", by Flashbang, for my Sig P238. It's a clamshell holster that tucks into the side band of the bra, and is secured by a leather strap and a small clip that hooks over the edge of the cup. I personally found it difficult to conceal the protrusion of the clip, as it poked outward, so I removed it, and found it worked much better. If Flashbang would make this clip flat instead of curved, I think it would be perfect. The holster will shift a little without the clip, but it's a lot less noticeable than having something poking out noticeably from under the side of your shirt.
The Marilyn does give the chest a lopsided appearance, but is probably less noticeable with a looser fitting top. I will continue to use this holster after pregnancy, so I'll experiment with other tops then. In the meantime, I hope this helps!