No symptoms anymore?

Up until 12 weeks I literally felt like I was dying of a constant hangover with sickness and dizzy all day everyday, woke up one morning and since then not a single symptom? I'm currently 15weeks 2days anyone else feel this way? I know I should be great ful I don't feel crap but atleast when I had my symptoms I knew baby was in there and ok but I can't help but over think things like heart might have stopped :/ silly I know.