First ultrasound at 6w5d

I just had my first ultrasound. The baby is measuring 6w3d, according to my LMP it should be at 6w5d but I have had my <a href="">IUI</a> done on CD16 so I've ovulated late. We saw hearbeat, two ovarian cysts that are normal and good to have to produce hormones to support the pregnancy (per my doctor). Next ultrasound is at 8 weeks when we are supposed to actually hear the heart, not just see it! 
Still feels unreal. 
The tiny white speck is the heart beating