12 weeks and sickness has slowed

I’m 12 weeks today and have suffered with sickness since 6 weeks, not everyday but I had some very bad days! The last time I was sick was last Saturday and was suffering bad heartburn! I have not been sick just felt nauseous and low energy levels. Is this normal for it to start subsiding now?? As much as I don’t want the sickness it was a sign things were progressing! I have a scan on Thursday I just get so worried the days before! I do however seem to have ‘popped’ a little over night!