Yep for most folks 4 weeks is very very short. Normally whats done is 2 weeks to let blood levels come down, 2-4 weeks of clomid therapy (some use nolvadex + clomid, some use HCG during cycle also), and then 10 weeks would begin of recouperation. Still yet others count that whole 14-16 week as the cycle and use that as thier time on = time off schedule, making 2 cycles a year about all that can be done.
To really know what your levels are you would have a blood test before to compare to, and almost everyone that I do find that has had thier post cycle blood test done are supprised at how low thier natural test is, and sometimes cholesterol levels, blood cell counts red/white, liver values etc can be out of whack depending.
Your test levels should still be 300 if not more I'd say, what does it look like?