My LMP is 10th December..I had an Ultrasound on 31st Jan..the age as per Ultrasound was 6 weeks 4 days & as per LMP its 7 weeks 3 days..there was gap of 6 days..In today's ultrasound age is 8 weeks 4 days i.e. gap increased by 3 more days (in total 9 days)..is it normal?