Anxious About Super Early BFP

Hi ladies, I just wanted to reach out and ask for thoughts because I am super overwhelmed. First off, I had ZERO signs of what turned out to be pregnancy. I already have 2 boys under 2 and was NOT expecting this! My husband and I didn't even have sex the week of my ovulation (according to Glow). The ONLY reason I took a test was because I was feeling a bit crampy (didn't think ANYTHING of it) but since my husband and I were on vacation and planning on doing some drinking at the casino, he asked me to please take a test beforehand to be safe. I agreed, waited the 3 minutes before pulling my test out of the wrapper ready to show him a very negative test only to be COMPLETELY SHOCKED! The darkest lines I've ever had, especially being 5 days before my next period. Has anyone else has such dark lines this early on? My sister is trying to scare me with the thought of twins and high HCG😂 I'm so overwhelmed. I didn't know whether I even ever wanted anymore kids...my husband and I were so careful. Please, any advice and word of encouragement are so welcomed. Thank you...