Is it a Possible Miscarriage?

*Im a 18 yr old female, and my last period was on december 10, and i had sex on DEC 24th, and on January 7th, I took a PT, and it was positive, and then on the 9th, i took another one, and it was positive, i was scared at first, but then after it finally sanked in i was gonna be a mother and i was so excited...so lets Assuming im about 5 or 6 weeks from my last period, But not counting that would make me only 3-4 weeks PREGNANT FROM THE DATE OF CONCEPTION so then i made a dr appt, and that hasn't even came up yet, because its not till January 25th, and so on the 18th at around 11pm i went to the bathroom, and wiped and saw blood, i started freaking out, crying and everything, i told my mom, and i asked her, and she said it happens sometimes, or i could be having a miscarriage, i had slight abdominal pains, but not severe, like 1-10, like 4 or 5 at the most...so i was begging her to take me TO the emergency room, and she finally did at 2am on the 19th... they took me in right away, took my blood, and did a US, the US concluded that they didn't see anything in there, and she also said it might even be to early to see anything, and if my dates are correct that i gave her, so they didn't see anything, but then i waited for about 1 hr to get the blood test results, and it said it was positive but with a low level of the HCG HORMONE Level, so the dr said that it might be the chances of a miscarriage, and it might be to early to tell, so on the 25th i go to my OBGYN, and i really hope that im not having a miscarriage, even though chances are that i am are like 85% im assuming, im still bleeding, and i have small clots, but the bleeding isn't enough to soak up a pad in one hour..., my stomach feels hard when i press on it, and my pains are barely there and my breast feel more fuller, and kinda sore...im so confused, i wish i knew what was going on in my body and i have been very emotional and iritated lately very easily...WHAT IS GOING ON WITH ME? ive heard of people bleeding long and they have had successful healthy pregnancys, but I dk, imm so scared, I have been so depressed just the thought of having a miscarriage, and when i see blood, it makes me wanna cry, but if i am Miscarrying?...These are my questions and concerns....

1. How long does the bleeding usually last for?
2.How long till the HCG level is gone and won't be detected?
3.How long after you have a miscarriage should you wait to try again?
4.Can you have sex while miscarrying and get pregnant while you are miscarrying?
5.Is it possible that you could have twins and one of them in miscarrying, but would you see something this early in a ultrasound?
6.If I miscarried now, what are my chances of miscarrying aagain?

Please I am desperate for advice....please reply to my post!!...I would really appreciate it!!

YOu might be having a miscarriage. When I had one I bleed for about a month and some and I know people who bleed longer. Its takes a month for your HCG level to. the doctor should be taking blood to see what going on. you should wsit about 2 month to try again just so you can get your self together. the twin thing is possible to but the doctors wont know yet.