Gas leak?!

It’s after midnight and my landlord is on his way over because I’m smelling STRONG odors of natural gas. Initially I was told it’s due to them cleaning grease traps today in the restaurant below our apartment, but when I got home today then smell was not in our apartment, and now that I’m trying to sleep that’s all I can smell. I was starting to get a headache earlier.

Hoping that all is fine, but I’m almost 6 months pregnant. Can this affect baby at all? Has anyone else had a gas leak?