Cant find a sac or baby at 6 wks

Hi guys I need some advice if anyones gone through this please pop up! Im currently 6 weeks pregnant. This is my third pregnancy. My first was a partial molar which had to be terminated. My second was a successful pregnancy but Im having complications with my third now😫 Ive had slight cramping and as Ive had past experience it was bugging me so I went to A&E to get things checked. Had a scan and they couldn't find a baby or a sac, tried the internal and nothing cropped up!! The same thing happened to me for the molar pregnancy.. Im really scared I can only hope for the best right now. I know its not a wise thing to do but Im so stressed Ive been reading on the net for reviews regarding similar situations and Ive come across where some mums have said there was no baby at there 6wks scan, they were called in for another scan after a wk or 2 and a baby popped up.