Welcome to Justanswer
I can Understand your situation being stressful for you. However hopefully I would be able to help you out of this stress by helping you understand the situation in the best manner possible.
Now to answer your 1st question
1. I read these sores on the penis can be a sign of HIV Is it true?
Sores can form in early or late HIV infection however the location for these sores very unlikely for the penis and much highly likely location for these sores is the throat or mouth.
2. HIV test done after 7 weeks and after 9 weeks were negative - If the sore that appear after eight weeks was related to HIV then after nine weeks would my test have to come out positive ?
A. It is highly unlikely for the test to be negative at 2.25 months (9 weeks) if the sore was due to HIV infection.
B. The recommended period after which the probability of one having HIV infection falls drastically to virtually being none is when the test at 3 months or a period greater than that is negative.
So this means Good news for you :)
Hope this explained the situation in the best manner possible
Please leave a positive reply if satisfied. If you need further clarification please do let me know instead of any feedback