No sickness

I was super nauseas from 5 weeks to about 8 weeks. I'm currently 9 weeks and 3 days now and don't feel sick hardly at all anymore. I mean still have to pee frequently and have sore breasts and food cravings but it's like The nauseousness just went away over night one day. Is that weird? Should I be worried? Had my first ultrasound on December the 28th and baby was 8 weeks and 3 days then and had a heart rate of 167bpm. Everything was fine so I shouldn't be worried right.