I got the phone call acceptance in March for a picture book and am still waiting for the contract and here it is November. Is there anything I can do about this?Yes.
...Is it because I am unagented?No. ...At least, mostly no.
It's because you're not doing what an agent would have done at least three months ago: call or email the editor to remind her of this outstanding contract. Agents can do only that much and the editor will read between the lines: "You know and I know that this is bullshit, so get your crap together, damn it, or I'll sell this book someplace else... unless you have a really good excuse or some quality grovelling for this lateness."
Editors won't read the same thing into a reminder from an unagented author, because most unagented authors don't have a sense of where things crossed into bullshit. An unagented author should be a wee bit more pointed (but still pleasant and professional--try to express polite concern rather than escalating frustration and panic. Frustration and panic are common qualities in authors (and yes, I know sometimes it's the editor's own fault), but they're unattractive qualities).
You should get in touch with the editor and remind her nicely of the contract (she may truly be surprised to hear that the contracts people haven't sent it to you, so reminders are good) and express worry that the project may be losing steam at that publishing house, and perhaps give her a soft deadline (like, "I'd hoped to have this contract finalized by the end of the year").
If you get no response for very much longer, you'll have to be more pointed, and make it clear that while you would love for this project to be published at this house, you're afraid there isn't enough enthusiasm for it there.
Still no response? Withdraw the project.