Sudden change in period?

It’s my first time posting here so a bit nervous..

For some background:

I’m a very regular person when it comes to my period and usually experience a very heavy flow. However within the last’s couple of months my flow has become lighter and decreased to 4-5 days rather than 5-6. Then earlier this month I got what I believe was my period however it lasted only 2 days and it didn’t look like my usual cycle as the blood was more see through rather than dense.

While I thought it could possible mean I’m pregnant the last time I was sexually active was in March, and a condom was used as contraceptive.(my mom doesn’t allow me to use birth control) But if I was pregnant my period wouldn’t have came in the following months right? I already went to the doctor and begged my mother to let me go to the gynecologist to find out more... I also did a urinal test and am currently waiting on those results.

However I’m worried what to do in the case I am pregnant... I’m 18 and my mother believes that any sex before marriage is grounds to be disowned...

I’m late as of right now for my actual period but I don’t know where else to turn to ask something like this... any advice would be appreciated... thank you..

TLDR: Usually a extra heavy flow whose period has become lighter over the past couple of months, does this mean I could be pregnant despite last activity being in March?