They had Fat Man and Little Boy, after detonating Trinity, so one down, two ready to go, a few near ready cores, and a production pipeline in place to produce more at one a month or so .. (the exact number is on Alex W's Nuclear Secrecy blog .. my recollection is poor and from five+ years past).
The production rate of 3 bombs per month in August was expected to rise to 5 bombs per month in November, and 7 bombs per month in December. In 1946, it could rise much higher.
