There are quite a number of different test you can take that are approved by UKBA.
It doesn't need to be IELTS.
Here's the latest UKBA listing Here's the latest UKBA listing
It is technically possible that your qualification might be accepted by UKBA but you'll need to enter into quite a convoluted process to secure that exemption and additionally it will cost quite a sum of money to verify.
Sadly, very few courses from the Philippines are reconised at the required level.
Despite the inconvenience and costs associated with this English Language test, I suggest to you that you're best advised to just go ahead and do the test. But it's your choice.
Good luck