I am 26 and currently 26 weeks pregnant. 6 ish weeks ago I found a lump in the left arm pit. Straight away fear, panic and anxiety rushed through my body. I rang my GP the next morning to book and appointment, due to COVID I had a telephone call with a GP. The GP was very blasé and basically said don't worry, nothing is wrong it's a swollen gland. I accept this and glad of the reassurance. I had read on the government website if the lump remains for more than two weeks to let your GP know. I asked should I ring back if it doesn't go, he said it could last for months and don't bother. I carried on as normal; 3 weeks ago I found another lump but in my right arm pit. Again, fear, panic and anxiety crept in. I began to worry that if it was serious I wouldn't be seeing my unborn child grow up. This time is spoke to another GP who wanted me to go and see her so she could feel the lumps. I went and she felt the swollen lumps and both of my breast. She wanted me to get my bloods done to check my white blood count. Straight away I knew what she wanted them for. I was so upset my worst fears were coming true. Everyone was saying I will be fine. However that reassurance doesn't help when you think your life is in turmoil. A few days later my bloods came back as clear, although my GP still wanted me to have a mammogram just to be on the safe side, although she said she couldn't feel anything in my breast and due to my age breast cancer would be very rare. Again due to COVID I had a doctor call me from the hospital, she stated the same thing and said they will be swollen glands, due to my petite frame these thing are more obvious. 6 long weeks of worry, anxiety and sleepless nights are now over, I can again start to enjoy my pregnancy. 
I am not the type of person to write on here or on a forum, however a colleague read some out to me when I was struck with fear and people's own stories helped me, so if I can give someone reassurance then I hope it helps.