[shimmeringfaerie]

Firstly, you are 15. Many younger girls don't get regular periods until their late teens. Even if you do have regular periods, there are many things that miss with a girl's cycle. Stress, especially about potential pregnancy, is a common cause of late or missing periods. Changes in diet, exercise, medication and so on can also cause late/missed periods.

The other symptoms you've noticed are also not necessarily signs of pregnancy. Needing to go to the bathroom more frequently can be caused by drinking more fluids, painful breasts are often a symptom of PMS, and blue veins are fairly normal. I also get nauseous at the smell of food on a regular basis and I know I'm not pregnant. It's also likely that you are just seeing these signs because you've convinced yourself that you are pregnant.

All that being said, the only way you are going to know if you are pregnant is by taking a test or going to the doctor's. I'm sorry, but posting several threads on a support site is not going to definitively tell you if you are pregnant. A test will and you need to take one as soon as humanly possible.

Though if I may ask, why is your ex-boyfriend so convinced that you can't be pregnant? Is he just in denial or does he have an actual reason to think that?