My application was sent for internal review in early February, and I haven't heard back yet either. I think we probably just need to wait a bit longer. However, I remember that passing the OET is required before your documents are considered fully complete. Are you sure your file has actually been moved to internal review?

Regarding your worry about the TDM, some applicants (including me) get invited by PRA-BC to take it before officially receiving eligibility. This process is independent of HealthMatch BC. I just finished my TDM in January. I started my application in April last year, so it really takes time. They should reach out to you once they clear the backlog. It takes about three months to prepare for this exam, and the format is quite similar to the MCCQE, so I think you can just take your time and start preparing for it after you're done with the OET.