Sarah Rees was working for a large charity when she fell pregnant with her first child and took maternity leave.
She was keen to return to work quickly, but her attempts to contact her employer were met with silence.
Eventually she was made redundant, and she could not afford to take the case to a tribunal.
Ms Rees says her experience is not uncommon, and a new report says many employers still live in the "dark ages" when it comes to recruiting women.
In a poll for the Equality and Human Rights Commission (EHRC), 36% of employers thought it reasonable to ask a woman about her plans to have children.
Some 59% agreed that a woman should have to disclose during the recruitment process whether she is pregnant.
The commission said the poll of 1,106 male and female decision-makers showed worrying attitudes.
'I realised I wasn't wanted'
Ms Rees, who lives in Cardiff, said she wanted to return to work when her daughter was 12 weeks old: "I loved my job," she says.
She emailed the organisation but did not receive a reply. She then popped into the office one day.
She says the atmosphere was "very cold and icy" and there was "no comment" when she said she wanted to talk about returning.
"Because no-one had contacted me I did things like I looked at the company website and I realised that I had been removed from the list of staff, so things started to add up and I realised I wasn't wanted any more," she told the BBC.
The position was driven home when a trustee contacted her because she was concerned the charity was discussing Ms Rees' redundancy without her knowledge.
Ms Rees did receive a formal notice of redundancy, but she decided against going to an employment tribunal because at the time she would have had to pay for it and she could not afford it.
"Also I didn't want to go into anything so difficult when I was already in a very stressful time, being a new mum," she says.
She says her experience is not uncommon. She now runs her own business helping women get back into the workplace and she says she heard of "plenty" of other people who have had similar experiences.
'A depressing reality'
The EHRC said its study showed that many employers needed more support to better understand the basics of discrimination law and the rights of pregnant women and new mothers.
EHRC chief executive Rebecca Hilsenrath said: "It is a depressing reality that, when it comes the rights of pregnant women and new mothers in the workplace, we are still living in the dark ages.
"We should all know very well that it is against the law not to appoint a woman because she is pregnant or might become pregnant.
"Yet we also know women routinely get asked questions around family planning in interviews."
Other findings from the YouGov survey of small, medium and large firms included:
- 46% of employers agreed it was reasonable to ask women if they have young children during the recruitment process
- 44% agree women should work for an organisation for at least a year before deciding to have children
- About one third believe that women who become pregnant and new mothers in work are "generally less interested in career progression"
- 41% of employers agreed that pregnancy in the workplace puts "an unnecessary cost burden" on the workplace
- 51% agree there is sometimes resentment towards women who are pregnant or on maternity leave
- The EHRC said its survey revealed antiquated beliefs, including two out of five employers saying women who have had more than one child while in the same job can be a "burden" to their team.
The EHRC wants companies to sign up to its Working Forward initiative which aims to stamp out pregnancy and maternity discrimination.
Member firms, which include Nationwide, Royal Mail and Transport for London, are given advice and help to improve in areas such as flexible working and employee confidence.
Ms Rees, whose second child is now aged one, advises women to make sure that they discuss clearly with their employer how they want to go back to work and to "join your trade union, because it's something that I didn't, because thinking I was working for a charity that I'd be protected".