How do you say I have butterflies in my tummy welsh?

There isn't a direct translation for "I have butterflies in my tummy" in Welsh. However, you can express a similar feeling using different phrases:

* Mae gen i chwerthin yn fy nghymdeithas. (This translates to "I have a giggle in my stomach" and is a common way to describe nervousness.)

* Mae gen i'r cyhyrau'n gysgu yn fy nghymdeithas. (This translates to "I have muscles twitching in my stomach" and emphasizes a physical feeling of anxiety.)

* Mae gen i ofn bach. (This translates to "I have a little fear" and is a straightforward way to express nervousness.)

The best phrase to use depends on the context and how you want to express the feeling.