Can you be pregnant and not even know that you are?

Rebecca

So I know it’s been a while since my husband and I had sex but today I noticed that when I got home from work today after eating dinner that I was changing clothes and noticed that my stomach was sticking out more than normal which is something I don’t really pay a lot of attention to on a daily basis during the week.

Can someone please tell me if it is possible to be pregnant and not even notice it until way later on?

I’ve heard that it is true but yet I just sometimes wonder if that is the case this time with me even with a negative test results.