I think it is a little early to be blooming in your area. Give it a little more time. I would not fertilize until after blooming starts. Al

If it has lots of seed pods, then it might be overburdened by seed development. I think you should clip the seeds off and see what happens in a few days. There's not much mistaking flower buds for seed capsules, so you can feel safe in doing that, I think.

As far as the watering goes, your schedule is meaningless to us. Watering should be done on an 'as needed' basis, and that can only be determined by you. The size of the plant, vigor, kind of potting medium, the container, temperature, humidity, and all other sorts of factors influence watering frequency. Lantana doesn't need a great deal of water (in frequency) but in containers, they're hostages, so to speak. Feel the soil and water heavily when it's too dry.

What's important is that you water thoroughly when you need to and allow the plant the opportunity to breathe in between.

I have a variety of lantana in my window boxes. The weeping purple are doing very well. The mixed yellow and pink are doing fine. The white are OK, but the pink are hardly blooming. It has been very hot here for some time. I water them as needed and fertilize them once a week with Miracle Grow. I don't understand why the pink aren't blooming? I live in South Central Pennsylvania.