Yes, i did this for all my documents. I created them in Word and then saved it as PDF, word has option to save file as pdf, use that and don't upload editable word documents.
Also, there is an option to reduce document size in Word which I think is under File menu. You can use that prior to saving your document and that basically allows you to decrease the DPI of the images in the document and drop any cropped out areas of the image, resulting in a smaller document. Play with different DPI settings and then save as PDF and check the file size. If it is still more than what is allowed, lower the DPI by one more level and check again.