I feel guilty about telling early because I'm superstitious!

De
I knew this would happen. I'm just 5 weeks but my best friend guessed it...she knows I'm pregnant because I refused drinks and a cigarette (which I don't normally smoke). She asked me and I confirmed it with her. My fiancéknows too and that's about it. My sister asked me if I was over the weekend because I told her I had some news to share soon and I didn't say yes or no and so she changed the subject, noting that I'm"very superstitious" which I am! Two coworkers also asked after I ate a brownie that I immediately regretted. As in, I ate the brownie and felt awful after, making me gag. They both just looked at me and said are you pregnant ?! And I didn't say yes or no just that I didn't want to jinx anything!! 
I'm nervous, as this is my first and I want things to move smoothly. I feel crazy, but people just seem to know when others are pregnant!! 
 
When people ask me if I'm pregnant, I realize I'm more comfortable eluding their question elsewhere or changing the conversation instead of saying yes or no. Saying no would be lying but it's too early for me to want to say yes!! Does anyone else struggle with this early on?