I took 500 mg of aspirin before realizing i shouldn't because i am feeding. Should I pump & dump?

I just took some excedrin for a headache, ingesting about 500 mg of aspirin... so i do some research & realize "aahh! i'm feeding & shouldn't have taken this! aaah!" My baby is just 7 weeks... what should i do? can i still feed? do i have to dump? how much & when should i pump & dump? (I do have pumped milk in freezer.)