Chemical ?

Im about 5W & 3 days based off of My LMP i had my first scan today and we seen nothing 😞 is it possible its a chemical ? My Ob was hesitant on doing one because he said the chance of seeing anything was slim i have another scan in 9 days for him to confirm he said my uterus line is thickening and my " insides " definitely point to pregnant has this ever happened to anyone with a good outcome im just a little stressed out 💔