Sugar low after eating

Heather • 2 angel 👼🏽👼🏽 🌈 Mother to daughter born May 30 ❤️❤️

So over an hour ago I ate some left over chicken and shrimp pasta. Just checked my sugar because I wasn’t feeling too well (tired, kind of out of it) sugar was 51!! Never have I seen it that low. I ate a bowl of cereal this morning as well, that was around 9a. What is going on?