17 Month Old Fraternal Twin Boys: Does My Toddler Have A Speech Delay?

As if I didn't have enough stress, I've found more things to worry about!
With twin toddlers, it takes a lot of effort on my part to get through the day. Well-rounded, nutritious finger foods, more milk less juice, playtime, safety first, naptime calmness, bathtime fun, routine, a little TV and a lot of books, clean diapers, and so on.
I save most of my worry for right before bed when my Melatonin-ed, Valerian root-ed, Benadryl-ed butt is supposed to be winding down. The other night I was Googling and found myself on a Baby Center page for Warning Signs of a Toddler's Language Delay. After reading a couple paragraphs I suddenly went into panic mode and quickly texted my husband (who was downstairs saving us all from brain-crazed zombies via Xbox One). Join me in the freak out dear husband of mine. Of course he's super rational and wanted to know why I was still awake, why I was Googling shit, who made this "stupid list" and, after I told him, "what the hell they knew."
My main worry with Baby A is he does not respond to his name. He does not talk and only recently started babbling (like a week or so). While he waves (wildly with both hands) and shakes his head (sometimes randomly), he does not point. He's uses the consonant B but only B (Ba sounds). I don't think he understands bye-bye but he might understand no (or he might be getting upset because I raised my voice). He does not point out things of interest. These are all listed under "By 12 Months." I won't even start on the "By 18 Months" list because there's so much he's already not doing.
Baby B says two words: "Dada" and "Gaga" (for light as he is obsessed with turning lights on and off around the house). He sometimes waves his hand (more like opening and closing his fist), does not shake his head but does point. He's been babbling for a while now. I don't know if he understands bye-bye but he does understand no, although he doesn't stop doing what he's doing. He points at things of interest but just started doing this recently.
Their 18-month wellness checkup is approaching so I plan to wait (two weeks) to bring my concerns up with their pediatrician. My rational side thinks children develop at different speeds so I should try to relax. This side believes they are still young so, if there's a problem, at least it is being addressed at a young age. My irrational side thinks they are behind because I'm a bad mother and failing them! The ratio of rational to irrational fluctuates - right now it's 60% unstable and growing because Aunt Flo is approaching.
Compare, compare, compare. Ugh. Look at how much smarter, faster and better my child is than yours! I win at life!
God I am tired.