Discharge and burning:
Discharge and burning, including pain or bleeding can be caused by sexually transmitted infections, especially if you’re under 25 (chlamydia or gonorrhoea) or you've had a sexual risk e.g. change in partner or unprotected sex.
For women, changes in your bleeding pattern are very common, particularly on certain types of contraception (see Implants, Injections and The Pill especially the progestogen-only or mini-pill), and pain at a regular point in your cycle may be normal.