Went to see the GP regarding contraception and directly after had a chat with a friend who is a sexual health doc. She had just been on a course where she learnt that oral contraceptives and the vaginal ring may not be suitable for people on lamotrigine (which I am)
Now my GP definitely did not know this and I'm fairly sure that this information is new so it's just something to be aware of.
Obviously, speak to your doctor before making any changes to your meds or if you have concerns.