Please help me understand…

So Sunday 3/19 I took a pregnancy test.. I wasn’t supposed to start my period until the 22nd but got a BFP! I was having tender breasts, fatigue, SORE ALL OVER! And cravings like crazy… i also started bleeding as soon as I took the test weird right? So I figured I was starting my period alittle early. But was all old blood. Dark brown and not a lot at all. i made an appointment the next day (Monday) and they took my HCG levels. I got those back later that day and they were 600. They told me to come in the following day for an ultrasound (Tuesday). My stomach was sore and he said from the inside I was tender so he gave me an ultrasound to check for excess fluid and to see if I was having an ectopic pregnancy. Of course they couldn’t see much, there was no sac of course but my left ovary had a cyst rupture (normal). Today (Thursday) they re did my labs and my levels shot up to 2,619! Have any of you had this problem with an ectopic pregnancy? What where your symptoms? I feel 20 weeks pregnant right now I’m bloated, gassy, and have never had symptoms this early in neither of my 2 pregnancy’s… I guess I’d just like alittle reassurance. And hear some testimonies. My hcg levels don’t make sense. I should be 5w and 1d today. They should’ve Atleast been able to see a sac of some sort right? Something little? Idk I think it’s crazy how high in a 72 hour period that my levels didn’t double but more than tripled. I’m definitely feeling the horomones changes within my body… that’s forsure. Is twins a possibility?