After Seeing An Oncologist Due To Slightly High RBC On

After seeing an Oncologist due to slightly high RBC on the high side. He told me to start taking Baby Aspirin when I left his office. The hospital performed Spleen and Blood Gas and all is good. Seen the doctor 3 weeks later to informed me of the findings. When I saw him the following week I came down with Vertigo. Blood were drawn to check my RBC. It is the same and performed a Phlebotomy. A week has past and still not 100%. Could the Aspirin cause the Vertigo?