6 months ago while pregnant, had a stomach virus- i threw up a few times with fleck of blood (not bright red) and none after that. threw up all day and only had flecks the first few times. could it have been swallowed blood from my nose? what else?

Many sources: Vomiting can cause trauma at the junction of the esophagus and stomach. A tear can form and can be large or small. This is called a Malory Weiss tear but usually heals on own unless severe bleeding requires an intervention. You can have blood from mucous membranes as well in the oropharynx or esophagus. Sounds like you had self limited and minor bleeding. The site is not relevant now