Baby #2, Is this normal??

Okay so I am pregnant with baby #2 and my first pregnancy was extremely easy. Just went along for 9 months just getting bigger. My only symptoms with that was enlarged breasts, swollen ankles, the belly of corse, heartburn and a lot of saliva.

This time I am 6 weeks and already I’m having back aches and my vagina is itching like I have covered it with poison ivy and I smell like dead fish. On this app it has a section for smell and itch but when does it go away?? How bad is it supposed to be? I know every pregnancy is different but does this mean it could be a girl this time? Or did I do something wrong? How to I calm the itching and is this all normal?