Hi
The behaviour that you have described may be consistent with an issue with the Digital Crown's operation.
The following steps may help:
Remove any case, bumper or screen protector that may be fitted to your Apple Watch.
Follow the instructions here to clean the Digital Crown:
If the issue persists, then I suggest that you contact Apple Support (remote diagnostics and/or mail-in service may be available, if required), make a Genius Bar reservation or visit an Apple Authorised Service Provider to arrange for your Apple Watch to be checked and, if required, serviced: