WMLB, you don't need to wait, you can start the gel immediately, just rip off the patch and use it today. I do a split dose of one pump in the morning and one in the evening. I put one lot on my upper, outer arms and the other lot on my inner thighs - I do this to get a good spread and I have found it helps to put some on the lower part of the body to help with VA. However, you can put the whole lot on in one go if you suits you better - arms or thighs whichever you prefer.
I think you are doing the right thing by ditching the patches, I found them to be virtually useless. The gel really changed my life, it is far more effective and more flexible because you can adjust the dose to suit your needs and as you can see from this forum, it gets very good results.