Hi Seymo,
It sounds like a 'normal' low beta. A beta of more than 20 at my clinic 14dptransfer was a postive. Some early betas are high as they are twins or your donor just produces high betas for singletons as was the case with me. Some betas are low as they are singletons. Your beta sounds fine ok. Congratulations, lovely news BTW
best THK