Can't find sign of any pre-flower or pollen sacs, any tips for sexing or forcing my plants into flowering?

Hello Scott. Cannabis plants usually show sex about 8 to 10 weeks. I see yours is only 7 weeks old. You will need to have a bit more patience. To sex a plant without putting them into flower, take some clippings off the lower branches, long enough to fit in a glass of water. Take the leaves off that would sit in water and you want 3 or 4 leaves above the water. Put the clippings in a 12/12 light environment. The males will show first. Change the water daily with lots of oxygen in the water and just a bit of food (too much food and the salt in the food might burn the clippings) to help the clipping show its flowers. If your plants don't show you what they are after 12 weeks, then try clipping thing. Good Luck. Chuck.