Needing piece of mind.

Can someone please give me a piece of mind. I took my first test on 9/11 and both lines were dark. I decided to take two more tests today and the first line was dark and the second line was very dim on both tests. I freaked out and went to the store and bought the clear blue and the hcg and the clear blue said pregnant and the hcg test had two dark lines. I had a miscarriage 3 years ago to where the baby had died in me and I didn’t find out until 3 weeks later when they couldn’t find a heartbeat. I’m afraid that it could happen again and I just want to know what it means with these different tests? Thank you.