where’s my baby?

So I found out yesterday I’m pregnant. Took a clear blue + it said pregnant - 2-3 weeks. Now here’s what becomes confusing.

I had my last period 29th of August till the 3rd of September. I had sex twice that month. Once after my period + once in the second last week of sept. My period isn’t here and I’ve been cramping a lot. I went to the hospital due to pain and they confirmed I am pregnant. They did blood tests and saw my HCG levels were doubling and said I’m between 4-8 weeks pregnant. They also said they think it’s best to have a scan because they’ll be able to see the baby, so they did a scan this morning and couldn’t see the baby atall. They saw a little part in the womb which said it might be that but couldn’t see anything. Also checked the outside of my womb and said they couldn’t see anything there either. I’ve been told by all the doctors I’m definitely pregnant. They sat me down + said I could be miss carrying or having an ectopic pregnancy. I’ve had this similar situation before in 2017 where they kept me in for 3 days as they couldn’t see the baby what so ever as he was hiding under a patch of blood.

I’m so worried as we have been trying for such a long time now + this will absolutely break me into pieces if anything happens.

Please give me your advice and input as I’m a little lost.

xxxxx