"what are the chances of getting HIV if you used a condom"
Even assuming your partner was HIV positive, the virus cannot cross an intact latex condom.
The fact YOU never had pre-ejaculate nor ejaculated plays no role in YOUR risk of getting HIV from your partner.
And yes, most folks have some white on their tongue when they get up in the morning. This is NOT oral thrush which is typically seen at the end stage of the disease (when the patient has gone from HIV into AIDS) and is a very, very painful fungal infection, making swallowing very difficult).
I'm not sure what you want us to tell you. Like most who post here, we don't diagnose HIV by "symptoms" and the piece missing from this puzzle is that we don't know the status of the partner involved and (it appears) neither do you.
Ask your partner to get tested. Or wait the appropriate time for you to get tested.
On the bright side, it appears that the intercourse was stopped before ejaculation took place; thus even if your partner was positive, contact with the virus would be extremely minimal.
Also keep in mind that we're at the time of year where sore throats and the flu are pretty darn common.
All in all the odds are very, very much in your favor that your symptoms have absolutely nothing to do with HIV.
An excellent question would be to ask how she knows there is "nothing to worry about"?
In other words, if she engages in unprotected sexual contact on a regular basis, does she get tested for all STD's, including HIV?
Keep in mind that except for a short term bout of flu like symptoms shortly after transmission, HIV will have NO symptoms for many years after one becomes infected. There are many walking around infected and unless they get tested are totally unaware of this as they feel just fine and dandy.
From a legal perspective health professionals must ask a patients permission to inform others that that person is infected with HIV. This causes problems when a patient is HIV positive and has chosen NOT to tell his/her partner this and continues to engage in unprotected sexual contact with them and we know this.
However, you are not in that legal situation. Do you feel comfortable sitting down with your stepfather and discussing his health status with him?
Frankly, if he is deliberately engaging in unprotected sexual contact with these partners knowing he is HIV positive he is a health risk. If I were you I would let these women know this, encourage them to get tested and suggest legal action against your stepfather.
The particular tests you used provided excellent results in terms of your status...as well as you certainly waiting the length of time required to get accurate results.
It's not so much the tests that provide accurate or inaccurate result but rather that some folks who worry about that status will test only days after a potential encounter. If using antibody tests, the results of such cannot be considered accurate as their immune system has likely not yet produced enough of these antibodies to be picked by these tests.