HCG okay?

So yesterday I got my HCG results for 14 dpo, 4 weeks pregnant. They were 45. She said they were lower than they like to see so I have to go in on Monday to make sure they're rising. I need someone to help me relax! Lol. Do my lines look like they're getting darker? This is my first pregnancy and I'm so scared. It took us over a year and we want this baby so badly. I also don't drink that much throughout the day (I'm trying to do better) so maybe that has something to do with it? I read somewhere if you're dehydrated, your HCG rises slowly. Thank you for any input!!