What could it be ?

There a such thing to bloat at early pregnancy ? I measured my stomach just to be doing something and I notice my stomach grew 3 inches ...

When I first found out I was pregnant ( on the 15th ), I start to measure my stomach so I can measure throughout my pregnancy ... when I wrap the measure tape around my stomach it was 31" ... I measured yesterday it was 34 1/2" ... I thought it was the food so I waited the next day to measure again and it was the same ...

Now , mind you I was told at the hospital I was having an "threatening miscarriage" ... so at this point I'm confused