some pregnancy tests are now sensitive to give you an accurate result 6 days before your missed period. but every women is different so you may have to way.
this early in pregnancy, especially your first, your stomach will not get bigger though. most women with their first, don't start showing until 4-5 months.
if you are not pregnant, don't be discouraged. you have not been trying long, the average time it takes a women to get pregnant for the first time is 6 months to 1 year. try testing again in a week, good luck!
It is very posible that you could be pregnant. Thats how I knew I was pregnant with my first son. My stomach was bloated, not a lot where others would notice but I could tell. It freaked me out at first lol. I think waiting until the 20th before testing is a good idea. Make sure you are testing with FMU. If it is still negative and AF still isnt showing wait and test again a few days later. I am currently 10 days late and still getting BFNs so Im waiting until Saturday when I will be officially 2 weeks late to test again. GL and sending you lots of baby dust!!!
There's a chance you might be but everyone is different I got to 6 weeks without a clue that i was pregnant. They only thing you can do is sit back and wait, chill out & good luck :)