Had sex for first time with new bf. white sponge like clumps in vagina few days later. no other symptoms no discharge. should i be concerned? yeast ?

Yeast infection: Could be developing. You may be too early for symptoms. Other alternative is an std. See your doctor if you are concerned

Yeast infection?: What you describe is probable and you can get several OTC products from your friendly pharmacist. If these do not work suggest you see a doctor and get diagnosed and treated face to face. Good luck.