HELP!

I had a miscarriage almost a year ago and I am having signs of being pregnant again I feel very bloated boobs are very sore lower stomach cramping and feeling sick at night I took a test it has one dark line and one faint line I took another test the next morning and it only had one line I'm scared that if I am I will lose this baby as well any advise to relax my nerves some??? Kinda scared!