Hi Shazz,
I too am on progesterone pesseries. They upped my pesseries 3 weeks ago to 2 x 200mg in the morning and 2 x 200mg at night. I have had some brown spotting and also had a bleed the night before my BT to tell me whether or not I was pregnant - my results came back at HCG 220 and 24 prog. They told me that a lot of women have break through bleeding sometimes up to the 3rd or 4th month and that it was nothing to worry about as long as the numbers keep rising and there is no clotted blood.
I feel the same I can't really enjoy my BFP as much as I want too, until I can get to week 12. Hang in there
your numbers sound good and strong.