Mood swings - For the 1st week, the ratio of test to estrogen is high; test will be relatively high compared to estrogen. You feel upbeat, focused and have a greater sense of wellbeing. 2nd week, the amount of test drops by half (half-life). You don't feel as upbeat and focused as the 1st week and you usually experience an increase in estrogen due to some of the test being converted to estrogen.
Man tits - With the increase in estrogen, you retain water and, if you're not taking an estrogen blocker, you eventually start getting gyno (man tits).
This is why you should be taking it every week and you should be taking an estrogen blocker.