Rheumatoid Factor and ANA Negative! Yay!?

At first, I was ecstatic that my test results for rheumatoid factor and ANA were negative.  Meaning probably not rheumatoid arthritis nor lupus.  But I did not know about another type of inflammatory arthritis that could go undetected by the two tests.  Something called ankylosing spondylitis.  This usually starts in the lower back, specifically the sacroiliac joints.  Arthritis could present in other parts of the body.  There's also the possibility that I'm too early in the progression of whatever it is that's ailing me to show up in a blood test.  The doctor wants to see me again in August.  So the best thing I could do is just keep track of any major symptoms and let her know what's up.  So far the following since October 2017 developed arthritis:

• Right thumb
• Left thumb
• Finger stiffness in both hands
• Right hip gives out due to stiffness
• in the morning, especially the day after standing a low
• Left hip started giving out on March 17, 2018 after standing a lot 
• Burning pain in lower back after entertaining for a couple of days and throwing a birthday party.  Lots of cooking and standing involved.  Since the fall of 2013 the joints around my hip area started to get painful after only standing for 2 to 3 hours.  I still have the same problem.
• Lower back always sore.  I try to do stretches periodically to prevent stiffness.  My back can get really stiff after standing up a lot.

I searched my genetic data to see if I'm a carrier of any HLA-B27 alleles, which increase the risk for ankylosing spondylitis but did not find anything.  However, there are HLA-B27 alleles that are not tested by 23andme.  Since my late biological mother developed arthritis when she was relatively young (30s-40s), I'll keep an eye out for any symptoms that could indicate ankylosing spondylitis.  She did not have the means to get checked out for her arthritis so I'm not sure if it was due to not taking care of herself or if there was a hereditary component.  

I don't want to dwell on what's hurting all the time, but I'd like to know what it is in hopes of being able to treat it.  My dad seems to think that my issues are not normal for someone my age and presently the only person that seems to take what I'm going through seriously.  I'm glad I have at least one person that has sense enough to see that this is not normal and wants to get to the bottom of it too.