Too early to see and positive turns negative????

Hello everyone! I found out I was pregnant a couple days ago and the app says I’m now 4 weeks and 5 days. I had extreme cramping on Saturday so went to the ER, they are saying it’s a possible ectopic but it’s too soon and they don’t see anything at all? I am going to the OB-GYN today for a second ultrasound. Any ideas if it’s still too soon to tell? I’m really worried about this!

Update- I went to the OB-GYN and they had me retake a pregnancy test and it came back negative (I took 8 at home Friday and they all came back positive and the hospital Saturday gave me one and it came back positive). They wouldn’t do a blood test on me to see what’s going on and refused to give me an ultrasound that the hospital told me I needed. Any idea why all of a sudden it shows negative?

Update- the doctor had a false negative, I took two more and went back to the ER since their previous orders were if I couldn’t get an ultrasound in 3-4 days to come back. They now see a sac that is about 4weeks and 5days. However my hcg levels are reading 6weeks and 5days. They said not to worry about the hcg levels that everything is fine. Now I’m only worried it could be twins!! Especially since multiples do run in my family!