nausea question

this is my 2nd pregnancy. My 1st, i had a boy and nausea for about 2 weeks straight..couldnt stand long enough to make toast. With this pregnancy, I haven't had any nausea..it's so strange. I mean, i got a pretty bad upset stomach a few times..mostly after eating and that led to some nausea but i had diarrhea from it..felt fine after. I have a great appetite..i am always hungry and nothing makes me grossed out. I think I'm thinking too hard into it but to those who have bad nausea...is it constant, random, do you get a stomach ache 1st anf that makes you nauseous? i find it odd i havent had it and it makes me get a little worried.