connect-mongo sessions collection is empty

Im using connect-mongo module for mongo session store

var express  = require('express');
var http  = require('http');

var mongoose = require('mongoose');

var db = 'mongodb://localhost:27017/test';

mongoose.connect(db);

mongoose.connection.on('open',function(db){
    console.log('connected ??')
})

var MongoStore = require('connect-mongo')(express);

....

app.use(express.cookieSession({
    secret : 's3cr3t',
    store  : new MongoStore({
        mongoose_connection : mongoose.connection
    }),
    cookie : {
        maxAge : 60000 // 60k msconds
    }
})

I can see connected? logged . but when i open mongo try db.sesssions.find() it reutns nothing . I gave requests with incognito , ie ,cleared cookies but the db is just empty but the test db and sessions collection are created