Congratulations on all your progress!!
It is safe to continue dilation throughout your pregnancy. As your belly gets bigger, finding a comfortable position for dilation might be a little more challenging. But you can always just have your partner insert the dilator for you, if reaching down and inserting yourself is difficult.
I have had some patients in the past have a few sessions with a pelvic floor physical therapist while pregnant to get specific exercises to help aid in a vaginal delivery, so you can look into that.
Strengthening abdominal muscles will be very helpful.
As well as learning good breathing techniques.