Why did my penis size decrease suddenly?

You have premature ejaculation. It is the time you cum too fast while having sex. It can arise from stress, anxiety, or low experience. Try to be calm and act gradually. You may also want to change positions or discuss it with your partner. It is normal to have this problem and you can learn how to control it. 

Boys your age ofte­n experience­ fluid release, known as e­jaculation. It's natural as you mature. This fluid may emerge­ during the day or at night when excite­d thoughts arise. Though frequent, the­re's no need for conce­rn. It signifies your body's developme­nt stage. Maintain healthy habits – nourishing meals and physical activity. 

Take a deep breath; this is quite a typical phenomenon and there is no need to freak out. When the sperm does not ejaculate for a while, it may be ejected by the body automatically, even in the lavatory. This is because the old sperm becomes obsolete and your body needs to get rid of them. Don't worry, it's all too normal. Just keep the genitals clean and maybe masturbate from time to time so as not to experience this.

Yes, it is possible for her to become pregnant even if you didn’t ejaculate inside her completely. There are still sperm in pre-cum that can result in pregnancy. If she has symptoms such as a missed period, feeling sick or throwing up a lot, or her breasts being sore and tender – then it is possible that she may be pregnant. To avoid this, use protection every time you have sex. 

White fluid is quite common, which is the case while you are on PEP tablets. This is not a problem. The white liquid is most probably the discharge that can occur when these medicines are taken. It's the body that discards extra matter. No additional medicinal treatment is required to cure this. Stick to your PEP and complete the full course of 28 days. 

At night, your body goes through change­s. Hormones shift, bladders fill up, and dreams stir. For ye­ars on end, these factors can cause­ wet bedshee­ts. Yet it's wise to speak up if it pe­rsists for four straight years. Trusted friends or he­alth experts can listen, pinpoint the­ reasons, and suggest methods to be­tter manage things.

These signs might be because of many things such as stress or bad eating habits. But don’t worry, your brother’s test result was negative which is good news but to ease your mind, you should also take an HIV test among others after discussing with a doctor about the issues at hand.