Opinions, thoughts please

Hey guys so I’ve had already about 2 miscarriages and I recently found out I’m expecting. Went to the doctors today and was spotting a little and did an ultrasound turns out I’m measuring 6w and 5d but I’m supposed to be 10w and 2d today so I’m a bit confused it’s either my dates are off orrr the fetus isn’t developing. What do you guys think of all this? has anyone ever went thru this? I’m a bit hopeful but scared for another miscarriage to happen