I have nursed all 6 of mine, and I am still nursing my 17 month old. I do not think it's a sign to wean at all, your little one is just testing the chompers. I have heard many things, some people have even said to tug a little piece of hair and say no. I just made the baby stop nursing and say "no bite!". Just do not laugh if the baby laughs at that reaction like my little sweet princess did
That just encourages it. She will still bite sometimes now, but its not intentional. It's only when she is dozing off and not realizing it. The last 4 of mine have not really even eaten much solids let alone drink much other than breast milk until they were around a year old.