Claire Holland, 32, was a keen Facebook user, and a campaign has been launched on the site to appeal for information as to her whereabouts.
Claire was last seen leaving the Seamus O'Donnell's pub on St Nicholas Street, Bristol, and despite usually logging on to Facebook at least once a day, has not accessed her account since June 6.
Detective Inspector Edward Yaxley from Avon and Somerset Police said they urgently needed 'to find Claire safe and well'.
"I would urge anyone who was with her on the day or night that she went missing to contact us," he said, "I am also keen to speak to anyone who may have seen her since or who may know where she is, or if she was in any trouble or worried about anything."
She was reported missing when she failed to turn up for a number of meetings some 10 days after the last sighting of her.
"Everyone is frantic not knowing that you're safe and well. You're not in any trouble, so please get in touch as soon as you can, we can help you and arrange anything that you might need. We miss you," they said.
The young mum is white, around 5ft tall with a small build and shoulder length brown hair. When she was last seen, she was wearing black trousers, a short sleeved black top with a grey t-shirt underneath, and was carrying a cream coloured Primark re-usable carrier bag.
Detective Yaxley added that he was 'extremely concerned for Claire's welfare' and said that it was 'completely out of character for her not to make contact with her family or friends'. He also said investigations showed that her bank account and phone has not been used since her disappearance.
Anyone who knows where Claire is or has any other info about her whereabouts should call Bristol CID on 101 quoting reference MP2251/12.