chest injury ?

I've used no steroids.

About 8 months ago I hurt my right chest muscle(right in the middle of the chest muscle going towards the shoulder) doing explosive bench presses without a very good warmup.(stupid) I didn't feel ANYTHING right away. I continued my workout for about another hour and thought I was fine! It started hurting the next day. There was no brusing/swelling or any visible damage. I had almost all my strength(a week later I benched and was maybe 10-15 pounds less strong and didn't hurt myself). The pain was weird. It hurt/ached when I was lying down or simply standing. Any movement, especially reaching over with my right hand to change the radio station hurt it. I stopped lifting and the pain went away after about 5 months.

For the past 3 months I've been ok and have done no lifting, but then it started aching a little in the past week.(just a slight barely noticeable ache)

Can someone tell me what's going on?(I went to see a sports doctor about 4 months ago and he said I was ok, the muscle had healed).

What kind of injury is this?

Also, I'm planning on starting a cycle to gain strength.

I know these dosages are low, but I'm looking to gain stength mot bodybuild. If I up the dosage, I'll simply have to cut back intensity to avoid tendon injury(from the muscle getting too strong too quick and the tendon not adapting) which is completely stupid. 10mg/day d-bol = 5 times normal level of endogenous test.
Would you recommend 200mg or 300mg or primo?
Reps will be 2-5 reps hitting major compound movements only. Squat/bench/dead/lunges/pull ups. No olympic style lifting will be done. Powerlifting workout.

Here's my rookie cycle:

Week Dianabol Primo

1 15mg/day 200-300mg/week
2 15mg/day 200-300mg/week
3 same
4 same
5 same
6 same
7 terminate d-bol(no pun) 200-300mg
8 cut primo dosage in half
End
Start clomid 100/day for first week 50/day for second week.
Off for 8 weeks.

I don't want people who say the pro bbers use 10 grams a week of test tell me that I'm using too little. I'm not a bber. I want to take it slow.

Thanks for any input guys.

Can I keep most of the gains made on a strength cycle like this?
Will I injure myself doing low reps?
I've been lifting for about 8 years(since I was 16).