Likely salivary duct
These are likely your salivary ducts under the tongue on each side of the strand of muscle that you see when you raise your tongue.
If you have rough/sharp edges on your lower front teeth and have been sticking your tongue out over them, then this is probably the cause. Warm salt water soaks/rinses make help soothe the area. Monday is probably fine, but sooner if it gets worse. Good Luck.