IUI #2 - 12dpiui

I am not changing the titles of my posts yet because I want this confirmed first. I took a digital last night that said Pregnant and an EPT this morning that was positive but when I got home this evening the line was a lot lighter. Does that mean anything? It is a different brand than the kind I took yesterday because CVS didnt have anymore of the FRER so I cant compare the 2 days. I am getting worried. I was so happy and confident today and this has ruined it. I am anxious for the beta tomorrow and more anxious for the follow up to make sure that it doubles. I just want to see it double. I am so scared. Of course I am now watching Birth Day on Discovery Health and I am crying. This is making me even more scared. What if this isnt real? What if it was the trigger? What if it doesnt last? Is it possible go through the loss and heartbreak of a miscarriage followed by a year of frustration and infertility only to miscarry again? Will I survive it? I'm scared...