low stomach (muscle?) pain – 8.5 months post anterior THR

Hey everyone, I have posted before and my running has been going very well. I have been running about 4 times per week and usually doing 1.5 min runs alternated with 30 second walks. I have been able to work my mileage up significantly over the past few months and I am now typically doing between 30 and 40 miles of these run/walks per week. My pace has increased as well. I do some swimming every day (I am in South Florida) along with some strengthening and core work in the gym. I also do distance walking on my non run/walk days.

About 3 weeks ago I started to feel some low stomach pain on my right side (same side as my THR which happened July 1, 2020). I started to feel this low stomach pain the most when doing pull ups and when doing abdominal exercises. I stopped the pull ups and changed my abdominal exercises, but I still feel it when doing abdominal crunches and leg lifts. I have started to feel this low stomach pain more during my runs.  I am not sure if it is a low stomach muscle strain or something else. I will probably it checked by a doctor.

Have any of you experienced low stomach pain on the same side as your replaced hip? If so, what did you do about it? Thanks in advance for your input.