What should i do it's been 7 days and my child hasn't passed a quarter he swallowed?

Swallowed quarter: How old is your child? See pediatrician. Child may need x-ray to locate the quarter, which may have lodged at outlet of stomach (pylorus) or at juncture of small bowel with colon. Depending on location, intervention may be necessary (such as endoscopy).

Go in for an exam: It is sometimes hard to track the passage of such an object or whether he really swallowed it. A metal detector passed over the stomach ( I use it in my office) or x-ray can verify if it is there. If the kid is not having any cramping with it, feeding him stewed okra might encapsulate it and help it pass over the next few days. If cramping/colicky a GI person may need to fish it out from above.