Hi I'm a 5'6" female (or maybe 5'5') what size road bike should I get?

You should head into your local bike shop so that they can help you get on the right size bike for your build and purchase it. We can all take a stab at it, but in the end, you have to ride the bike so get the size that best fits your body.

Most manufactures will have a chart of size recommendations for their bikes.

My guess is you'll be looking at bikes somewhere around 50cm to 52cm.

However, as TenSpeedV2 mentions, ultimately you have to find a bike that is comfortable for your specific body proportions.

Agree probably around 52cm but best to use a good online calculator and/or go to the local bike shop.

Here is a good online calculator. https://www.competitivecyclist.com/sc/