So why do I have 66 posts but only 56 activity
It's not the number of posts made being counted, it's your activity. Even if you've made a lot of posts only 14 posts will be counted in every update. Below is a table of your post per day... so, I advise you to log-in daily (without fail) and make 1 quality post (that would be enough for a day) and you'll reach a rank of Hero Member in a matter of 480 to 490 Days.
1 X 14 = 14
2 X 14 = 28
3 X 14 = 42 >>> Jr. Member [30 Days - 42 Days]
4 X 14 = 56 *** this is your present activity Criptomen@30
5 X 14 = 70 >>> Member [60 Days - 70 Days]
6 X 14 = 84
7 X 14 = 98
8 X 14 = 112
9 X 14 = 126 >>> Full Member [120 Days - 126 Days]
10 X 14 = 140
11 X 14 = 154
12 X 14 = 168
13 X 14 = 182
14 X 14 = 196
15 X 14 = 210
16 X 14 = 224
17 X 14 = 238 ***my present activity
18 X 14 = 252 >>> Senior Member [ 252 days]
19 x 14 = 266
20 x 14 = 280
21 x 14 = 294
22 x 14 = 308
23 x 14 = 322
24 x 14 = 336
25 x 14 = 350
26 x 14 = 364
27 x 14 = 378
28 x 14 = 392
29 x 14 = 406
30 x 14 = 420
31 x 14 = 434
32 x 14 = 448
33 x 14 = 462
34 x 14 = 476
35 x 14 = 490 >>> Hero Member [480 Days - 490 Days]
Ref: https://bitcointalk.org/index.php?topic=178608.0