OP did the right thing. You made your message clear. However, it wasn't the right place nor time. This woman clearly did not give a shit about her health or her baby's health.
Here is the "make no bones about it"; it's her baby. Just like it's her body to do whatever she wanted.
Even if you did get your message across, you pretty much rewarded her. She got to let off some steam. She got free beer. She got you fired. She can now brag to the rest of her trashy friends about how she "fixed you good".
If someone disregards the very life they created, what makes you think they will care about yours?
So, it's your call from here on out; do you accept the heat you will receive from similar future situations but, do the right thing? Or, do you mind your own business and let the world rot?
Personally, I would let the world rot. The world heads in the direction we want it to. And, if most people want to slip off the edge and send humanity down a road of pain and suffering - so be it.
We were created with the ability to choose after all.