Should I Worry About Pregnancy Through A Brief Penetration On My Period With No Ejaculation?

Exactly early morning of July 7, me and my partner had intimacy. It is in the verge of our emotions that we didn t have control of ourselves and decided to try vaginal penetration for the first time around. It didn t go successful as my partner said that it was too tight and only the tip got to the vagina and didn t go that deep. My partner said that he was sure enough that there was no cum that went inside as the penis was only there for a few seconds and we didn t try again. I still don t want to have children and now I am constantly stressed and worried that I might be carrying a child. The time we had intimacy, I am on the early days of my period (I started July 5) and based on what I ve searched through net there are low chances of being pregnant while on period but it is still possible and it kind of freaked me out. I also searched if pre-cum can get someone pregnant and it said the same thing. There are low chances but still, it is possible. I have bipolar disorder and I think thinking about this made it harder for me to control my emotions and myself, I also had trouble sleeping. I am also worried because I am taking medications and in any case that I am pregnant (which I hope not) I don t know if it is allowed to take my meds anymore. I wanted to seek advice if I should worry that much about being pregnant based on the situation.