I started having issues with my automatic transmission yesterday on my 2009 Hyundai Elantra. I was driving to dinner when I noticed that my transmission changed gears all of a sudden and made a strange noise. After that happened, my car struggled to change from first to second gear, and would hesitate to change gears for a good 5-10 seconds. Once it was out of first it would run just fine until I had to stop again. I’ve had my car since 2009 and I have never had this issue. When I was driving back home, my car acted like nothing happened and continued to behave for the rest of the night. My fiancé checked the transmission fluid and noticed that it wasn’t leaking, but it was too dark to tell what color the fluid was. As far as I know, the transmission fluid has never been changed and my car is close to 87K miles. I was driving today, and when I was slowing down to turn into my parking lot, my car shifted the gears down quite abruptly and made a thump sound. It continued to drive fine when I was driving to my garage spot. What is causing this to happen? Would it be a good idea to get my car looked at by a mechanic? Any advice would be helpful. Thanks!!